Browse All 300+ Free Calculators

Basic Calculator

Free online calculator with memory functions, keyboard support, calculation history, and floating-point correction. Add, subtract, multiply, and divide instantly.

Exponent Calculator — bⁿ, Roots & Logarithms

Calculate any base raised to any power (bⁿ), find the base given a result and exponent, or solve for the exponent using logarithms. Handles negative, fractional, and zero exponents with step-by-step working.

Scientific Notation Calculator

Convert numbers to and from scientific notation and perform arithmetic in scientific notation.

Modulo Calculator — Remainder Division

Calculate the remainder of a division (modulo operation) for any two numbers.

Nth Root Calculator — Square & Cube

Calculate any nth root of a number including square root, cube root, and custom roots.

Number Sorter — Sort & Statistics

Sort a list of numbers in ascending or descending order. Find min, max, sum, and average.

Remainder Calculator — Long Division with Steps

Calculate the quotient and remainder of any division with full long division working shown step by step. Also computes the modulo and checks divisibility for multiple divisors at once.

Recipe Scaling Calculator — Multiply or Divide Servings

Scale any recipe up or down by servings or a custom multiplier. Convert between cups, tablespoons, teaspoons, and grams. Handles fractions, adjusts pan sizes, and notes ingredients that do not scale linearly.

Advanced Scientific Calculator

A CAS-level scientific calculator with graphing, matrices, complex numbers, derivatives, integrals, statistics, and equation solving — all in one.

Percentage Calculator

Calculate percentages easily. Find what percent one number is of another, increase or decrease by a percentage, and more.

Percentage Change Calculator

Calculate the percentage increase or decrease between two values quickly and accurately.

Markup Calculator — Profit & Selling Price

Calculate markup percentage, selling price, and profit margin from cost and revenue.

Percentage Discount Calculator

Calculate sale price, discount amount, and savings percentage for any original price.

Percentage Error Calculator

Calculate the percentage error and absolute error between a measured and true value.

Average Calculator — Mean, Median & Mode

Calculate the mean, median, mode, standard deviation, IQR, box plot, and more for any dataset.

Weighted Average Calculator

Calculate the weighted average of values with different weights.

Ratio Calculator — Simplify & Solve

Simplify ratios, find equivalent ratios, and solve ratio problems.

Proportion Solver — Cross Multiply

Solve proportions by finding the unknown value in a/b = c/d equations.

Grade Calculator — Weighted GPA & Final Grade

Calculate weighted final grades, simple averages, and GPA from up to 12 assignments. Find what score you need on remaining work to hit your target grade.

Harmonic Mean Calculator — Rates, Speeds & P/E Ratios

Calculate the harmonic mean of any dataset. Compare H, G, A means, verify AM-GM-HM inequality, see reciprocal table. Weighted harmonic mean mode included.

Fraction Calculator — Add, Subtract & More

Add, subtract, multiply, and divide fractions and mixed numbers with LCM common denominators, cross-simplification, and full step-by-step working.

Fraction to Decimal Converter — Repeating & Terminating

Convert fractions to decimals with repeating-block detection, or convert terminating decimals back to simplified fractions. Supports mixed numbers and shows full step-by-step long division working.

Mixed Number Calculator — Add & Divide

Add, subtract, multiply, and divide mixed numbers. Converts between mixed numbers, improper fractions, and decimals with step-by-step working.

Unit Converter — Length, Weight & More

Convert between units of length, weight, temperature, volume, and more.

Number Base Converter — Binary, Hex

Convert numbers between binary, octal, decimal, and hexadecimal bases.

Speed Converter — mph, km/h, m/s

Convert between mph, km/h, m/s, knots, and feet per second.

Temperature Converter — °C, °F, K

Convert between Celsius, Fahrenheit, Kelvin, and Rankine temperature scales.

Energy Converter — Joules, kWh, BTU & Calories

Convert between 15 energy units: joules, kJ, MJ, GJ, Wh, kWh, MWh, cal, kcal, BTU, therm, ft·lb, eV, keV, MeV. Live results organized by category with smart formatting and NIST-sourced conversion factors.

Pressure Unit Converter

Convert between Pascal, psi, atm, bar, mmHg, and torr pressure units.

Data Storage Converter — Bytes, KB, MB, GB & TB

Convert between bits, bytes, KB, MB, GB, TB, PB and binary KiB, MiB, GiB, TiB units. Explains the 1 TB = 931 GB discrepancy between SI and IEC standards.

Fuel Efficiency Converter — All Units

Convert fuel efficiency between L/100km, MPG US, MPG UK, km/L, gal/100mi, and mi/L simultaneously. Includes efficiency rating and vehicle class comparison.

Angle Converter — Degrees, Radians, Gradians & More

Convert angles between degrees, radians, gradians, turns, arcminutes, arcseconds, and milliradians. Includes DMS mode and a visual angle display.

Power Unit Converter — Watts & HP

Convert between watts, kilowatts, horsepower, BTU/h, and other power units.

Quadratic Equation Solver

Solve quadratic equations (ax² + bx + c = 0) and find both real and complex roots.

Cubic Equation Solver — ax³+bx²+cx+d=0

Solve cubic equations (ax³ + bx² + cx + d = 0) and find all three roots with step-by-step working, graph, and factored form.

Polynomial Evaluator — Compute f(x)

Evaluate any polynomial at a given value of x using Horner method.

Logarithm Calculator — Log & Ln

Calculate logarithms with any base. Supports natural log (ln), log base 10, and custom bases.

Absolute Value Equation Solver

Solve |ax + b| = c and |ax + b| = |cx + d| with step-by-step case analysis, verification, and formatted solutions.

Linear Equation Solver — Solve ax+b=c

Solve linear equations in one variable (ax + b = c) with step-by-step solutions.

Systems of Equations Solver 2×2

Solve systems of two linear equations with two unknowns using Cramer's rule.

Inequality Solver — Linear & Quadratic

Solve linear and quadratic inequalities with step-by-step solutions.

Summation Calculator — Sigma Notation

Evaluate summation expressions with custom formulas, bounds, and step values.

Complex Number Calculator — a+bi

Add, subtract, multiply, divide, and apply powers and logs to complex numbers. Shows Argand diagram, polar form, modulus, and step-by-step working.

Completing the Square Calculator

Convert ax² + bx + c to vertex form a(x−h)² + k step by step. Find the vertex, axis of symmetry, and roots of any quadratic.

Synthetic Division Calculator

Divide polynomials using synthetic division and find quotient and remainder.

Rational Root Theorem Calculator

Find all possible rational roots of a polynomial using the Rational Root Theorem.

Exponent Rules Calculator — All 8 Laws

Apply all 8 laws of exponents — product, quotient, power of a power, zero, negative, fractional, and multiple-base rules — with step-by-step working and numerical verification for any base and exponents.

Logarithm Laws Calculator

Apply logarithm laws: product, quotient, power, change of base, and natural log rules.

Arithmetic Sequence Calculator

Find the nth term, partial sum, and common difference of any arithmetic sequence. Solve for any unknown and generate up to 1,000 terms.

Geometric Sequence Calculator — nth Term & Sum

Find the nth term, partial sum, and infinite sum of any geometric sequence. Solve for the common ratio or number of terms. Determine convergence with first 12 terms shown.

Simplify Radicals Calculator

Simplify radical expressions by extracting perfect square (or nth-power) factors. Converts √72 → 6√2, ∛54 → 3∛2, and handles variables.

Exponential Growth & Decay Calculator — y = aeʳᵗ

Calculate exponential growth or decay using y = ae^(rt). Solve for any unknown: initial value, growth/decay rate, time, or final value. Covers population growth, bacterial cultures, radioactive decay, investment compounding, and any continuous growth model. Doubling and half-life shown automatically.

Area Calculator — 11 Shapes with Formulas & Perimeter

Calculate area and perimeter for 11 shapes: rectangle, square, circle, triangle, right triangle, trapezoid, parallelogram, rhombus, ellipse, hexagon, and sector. Formulas shown with your values substituted in.

Volume Calculator — 3D Shapes

Calculate the volume of cubes, spheres, cylinders, cones, and other 3D shapes.

Perimeter Calculator — 2D Shapes

Calculate the perimeter and circumference of common 2D shapes.

Pythagorean Theorem Calculator

Find the missing side of a right triangle using a² + b² = c².

Distance Calculator — 2D & 3D Points

Find Euclidean, Manhattan, and Chebyshev distance between 2D or 3D points. Includes midpoint, slope, line equation, and SVG visualization.

Midpoint Calculator — Two Points

Find the midpoint between two points in 2D or 3D coordinate space.

Slope Calculator — Gradient & Line

Calculate the slope of a line between two points and find the line equation.

Circle Calculator — Area & Circumference

Calculate radius, diameter, circumference, and area of a circle from any known value. Supports sector angle input for arc length, sector area, chord length, and segment area. Includes 7 unit options, adjustable precision, SVG diagram, and 5 real-world presets.

Surface Area Calculator — 3D Shapes

Calculate surface area of cubes, spheres, cylinders, cones, and other 3D shapes.

Triangle Solver — Law of Sines & Cosines

Solve any triangle given SSS, SAS, ASA, or AAS using law of sines and cosines.

Coordinate Geometry Calculator — Distance & Slope

Calculate distance, midpoint, slope, line equation, angle, section point, and triangle area from coordinates. Includes an interactive coordinate plane diagram, triangle analysis (centroid, inradius, circumradius), and step-by-step working.

Ellipse Calculator — Area, Perimeter & Eccentricity

Calculate the area, perimeter (Ramanujan II), eccentricity, focal distance, semi-latus rectum, directrix, flattening, and standard equation of any ellipse from its semi-axes.

Regular Polygon Calculator

Calculate the area, perimeter, interior angles, and diagonal of any regular polygon.

Heron's Formula Calculator — Triangle Area & Angles

Calculate triangle area using Heron's formula (SSS), SAS, or base-height. Shows all angles via law of cosines, altitudes, triangle type, SVG diagram, and step-by-step working.

Circle Sector Calculator — Arc, Area & Chord

Calculate arc length, sector area, chord length, segment area, and perimeter of a circle sector. Supports 4 solve-for modes (r+θ, arc+θ, area+θ, r+arc), degrees or radians, 7 length units, SVG diagram, presets, and step-by-step working.

Torus Calculator — Volume & Surface Area

Calculate the volume, surface area, and other properties of a torus (donut shape).

Golden Ratio Calculator — φ = 1.618033…

Calculate golden ratio dimensions from any measurement. Find A from B, B from A, total length, golden rectangle dimensions. Shows Fibonacci spiral convergence to φ with up to 15 decimal precision.

Frustum Calculator — Volume, Area & Slant Height

Calculate volume, slant height, lateral area, and total surface area of a frustum (truncated cone). Supports 5 units, 6 presets, SVG diagram, and step-by-step working.

Aspect Ratio Calculator — Screen & Image

Calculate aspect ratios, scale dimensions proportionally, and batch-resize images or videos without distortion.

Map Scale Calculator

Convert between map distances and real-world distances using any map scale ratio.

Paint Calculator — Gallons Needed for Walls & Ceilings

Calculate exactly how much paint you need for any room. Enter wall dimensions, doors, windows, and number of coats. Supports walls, ceilings, trims, and exterior surfaces with waste factor.

Flooring Calculator — Square Footage & Materials

Calculate flooring materials for any room shape. Enter dimensions, choose flooring type (hardwood, tile, vinyl, carpet), set waste factor, and get total square footage, boxes needed, and cost estimate.

Trigonometry Calculator — Sin, Cos, Tan

Calculate sine, cosine, tangent, and their inverses for any angle.

Inverse Trig Calculator — Arcsin, Arccos

Calculate arcsin, arccos, arctan and get angles from trig ratios.

Right Triangle Solver — Sides & Angles

Solve any right triangle given two sides or one side and one angle.

Radians to Degrees Converter

Convert angles between radians and degrees instantly.

Unit Circle Calculator — Exact Trig Values

Find exact and decimal values of sin, cos, tan, csc, sec, and cot for any angle on the unit circle. Supports degrees and radians, shows reference angles, quadrant, and coordinates.

Derivative Calculator — Find f′(x) Instantly

Compute 1st through 4th numerical derivatives of any function at any point. Shows tangent line equation, derivative table, and interactive chart.

Second Derivative Calculator

Compute the second derivative and determine concavity at a given point.

Integral Calculator — Numerical

Compute definite integrals numerically using Simpson's rule and the trapezoidal rule.

Limit Calculator — Evaluate Limits

Evaluate limits of functions numerically as x approaches a value from left, right, or both sides.

Riemann Sum Calculator

Approximate definite integrals using left, right, midpoint, and trapezoidal Riemann sums.

Tangent Line Calculator

Find the equation of the tangent line to a function at a given point.

Newton's Method Calculator

Find roots of equations using Newton's iterative method with step-by-step convergence.

Arc Length Calculator — Curves & Circle Arcs

Calculate arc length for any function f(x) over an interval using numerical integration, or compute a circle arc length from radius and angle. Also shows sector area, chord length, and step-by-step working.

Partial Derivative Calculator

Compute partial derivatives of multivariable polynomial functions.

Taylor Series Calculator

Compute Taylor/Maclaurin series expansions for common functions.

Differential Equation Solver — ODE

Solve first-order ODEs numerically using Euler, Heun, and RK4. Compare method accuracy step by step.

Area Between Curves Calculator — Two Functions

Calculate the exact area enclosed between two functions f(x) and g(x) over any interval. Automatically detects intersection points, splits the integral correctly, and shows a sub-region breakdown.

Volume of Revolution Calculator

Calculate volumes of solids of revolution using disc and shell methods.

Laplace Transform Calculator

Find Laplace transforms and inverse transforms for common functions.

Fourier Series Calculator — aₙ, bₙ & Spectrum

Compute Fourier coefficients aₙ and bₙ for any periodic function using 2000-point Simpson's rule. Supports square wave, sawtooth, triangle, rectifiers, and custom expressions. Shows amplitude spectrum, coefficient table, partial sum, and Gibbs phenomenon detection.

Improper Integral Calculator

Evaluate improper integrals with infinite limits or discontinuities.

Series Convergence Calculator

Test if an infinite series converges or diverges using ratio, root, and comparison tests.

Standard Deviation Calculator

Calculate standard deviation, variance, and other statistics for a dataset.

Z-Score Calculator — Standard Score & Percentile

Calculate z-score, percentile rank, and p-values from any data point, mean, and standard deviation. Includes reverse calculation and step-by-step solutions.

Probability Calculator — Events

Calculate single event, multiple event, conditional, and complementary probabilities.

Correlation Coefficient Calculator

Calculate Pearson r and Spearman ρ between two datasets with p-value, R², regression line, and scatter plot.

Linear Regression Calculator

Find the best-fit line (y = mx + b) using least squares regression.

Binomial Distribution Calculator

Calculate binomial probability P(X=k), CDF, mean, variance, and distribution statistics for any n and p. Includes bar chart and full probability table.

Poisson Distribution Calculator

Calculate Poisson probabilities for rare event modeling.

Chi-Square Calculator

Perform chi-square goodness-of-fit and independence tests with p-value, critical value, effect size (Cramér's V, Cohen's w), Yates' correction, standardised residuals, and chi-square distribution curve. Supports 2–5×2–5 contingency tables with real-world presets.

Confidence Interval Calculator — Mean & Proportion

Calculate confidence intervals for means (z and t-test) and proportions (Wald and Wilson). Shows margin of error, critical value, SE, step-by-step working, and a visual bell curve diagram.

Sample Size Calculator

Calculate the required sample size for surveys and experiments.

Percentile Calculator — Rank & Value

Find percentile ranks and values from a dataset.

ANOVA Calculator — One-Way with p-value & Effect Size

Perform one-way ANOVA with up to 6 groups. Shows the full ANOVA table, exact p-value, effect size η², group statistics, and a significance verdict — no F-table look-up needed.

Bayes' Theorem Calculator

Calculate posterior probability P(A|B) from prior, sensitivity, and false positive rate. Includes natural frequencies, Bayes factor, and step-by-step derivation.

T-Test Calculator — One-Sample

Perform a one-sample t-test to determine if a sample mean differs significantly from a known value.

Variance Calculator — Population & Sample

Calculate population variance and sample variance from a dataset with step-by-step workings.

Quartile Calculator — Q1, Q2, Q3 & IQR

Calculate Q1, Q2 (median), Q3, interquartile range (IQR), and detect outliers from data.

Frequency Distribution Calculator — Tables & Charts

Build grouped or ungrouped frequency distribution tables from raw data. Shows relative and cumulative frequencies, modal class, estimated mean and standard deviation, and a bar chart.

Geometric Mean Calculator — CAGR & Rates

Calculate geometric mean for growth rates, investment CAGR, and multiplicative data. Compare AM, GM, and HM with warnings for zeros and negatives.

Moving Average Calculator — SMA & EMA

Calculate simple moving average (SMA) and exponential moving average (EMA) for time series data.

Effect Size Calculator — Cohen's d, η² & r

Calculate Cohen's d, Hedges' g, Glass's Δ, r, and η² effect sizes from means, t-statistics, F-statistics, or correlation r. Includes 95% CI, power, and required sample size.

P-Value Calculator — Z, T, Chi-Square & F

Calculate the exact p-value from a z-score, t-statistic, chi-square statistic, or F-statistic. Supports one-tailed and two-tailed tests with significance interpretation.

Mean, Median & Mode Calculator

Calculate the mean, median, mode, range, variance, standard deviation, quartiles, and IQR for any dataset. Detects outliers, shows sorted data, and supports both population and sample statistics.

Normal Distribution Calculator — PDF, CDF & Inverse

Compute exact probabilities for any normal distribution: P(X < a), P(X > a), P(a ≤ X ≤ b), inverse CDF (quantile), and PDF at a point. Works with standard normal (μ=0, σ=1) and custom parameters. Bell curve visualization included.

Compound Interest Calculator

Calculate compound interest with monthly contributions, solve for principal, rate, or time, and see a year-by-year growth breakdown.

Simple Interest Calculator — I=PRT

Calculate simple interest using I = P × R × T formula.

Loan Payment Calculator

Calculate monthly loan payments, total interest, and amortization.

Tip Calculator — Split Bill

Calculate tip amount, total bill, and split between multiple people.

Mortgage Calculator — Monthly Payment

Calculate monthly mortgage payments, total interest, and amortization schedule.

ROI Calculator — Return on Investment

Calculate return on investment percentage from cost and revenue.

Currency Converter — Live Exchange Rates

Convert between 35 world currencies with live daily exchange rates. Shows mid-market rates, rate table, and popular pairs.

Depreciation Calculator — SL, DDB & SYD

Calculate annual depreciation and full amortization schedules using straight-line, double declining balance, and sum-of-years-digits methods. Includes book value chart and method comparison.

Income Tax Calculator — US 2024

Estimate your income tax based on US federal tax brackets (2024). Calculate effective tax rate.

Break-Even Calculator

Calculate the break-even point in units and revenue from fixed costs, variable costs, and selling price. Includes contribution margin, CM ratio, safety margin, operating leverage, target profit planning, and a visual break-even chart.

Retirement Savings Calculator

Project how much you will have at retirement based on savings rate, return, and time horizon.

Inflation Calculator — Purchasing Power

Calculate the purchasing power of money over time using historical or custom inflation rates.

NPV Calculator — Net Present Value

Calculate the net present value (NPV) and profitability index of an investment.

Debt Payoff Calculator — Credit Card & Loan

Calculate how long to pay off any debt and total interest paid. Includes amortization schedule, extra payment comparison, and find-required-payment mode for credit cards and loans.

Savings Goal Calculator

Calculate how long to reach a savings goal or the monthly contribution needed.

Salary to Hourly Calculator

Convert annual salary to hourly, daily, weekly, and monthly rates.

Hourly to Salary Calculator — Advanced Pay Converter

Convert any hourly wage to annual salary, monthly, bi-weekly, weekly, and daily pay. Includes benefits valuation, contractor vs employee cost comparison, gross-to-net tax estimate, multi-currency support, and PDF/CSV export.

GST / VAT Calculator — Add, Remove & Multi-Item

Add or remove GST/VAT from any price. Multi-item invoices with individual rates. Country presets for Australia, UK, India, Canada, and EU. 6 currencies supported.

Bill Splitter — Tip & Split

Split a restaurant bill with custom tip percentage and divide equally among any number of people.

Annuity Calculator — PV, FV, Payment, Term & Perpetuity

Calculate present value, future value, required payment, or term for ordinary annuities and annuities-due. Includes perpetuity mode, step-by-step working, and a year-by-year growth or amortization schedule.

APR Calculator — True Cost of Any Loan

Calculate the Annual Percentage Rate (APR) and Effective Annual Rate (EAR) for any loan. Accounts for upfront fees, shows step-by-step Newton-Raphson solution, and compares two loan offers side by side.

Fuel Cost Calculator — Trip Cost & CO2

Calculate trip fuel cost from distance, fuel efficiency, and price per litre. Supports L/100km, km/L, MPG US/UK, six currencies, CO2 estimate, and step-by-step working.

Auto Loan Calculator — Monthly Car Payment

Calculate your monthly car loan payment with down payment, trade-in, sales tax, and fees. Includes a full amortization schedule, rate sensitivity table, down payment impact analysis, and side-by-side loan comparison.

Investment Calculator — Growth, Returns & Retirement

Project long-term investment growth with monthly contributions and lump-sum inputs. Compare conservative, moderate, and aggressive return scenarios, see inflation-adjusted value, and estimate retirement income using the 4% withdrawal rule.

Net Worth Calculator — Assets, Debts & Financial Health

Calculate your net worth by listing all assets and liabilities. See how you compare to Federal Reserve age benchmarks, check your debt-to-asset ratio, and find your financial independence number.

Budget Calculator — 50/30/20 Rule & Monthly Planning

Build a monthly budget and compare your actual spending to the 50/30/20 rule. Track needs, wants, and savings against recommended targets, check emergency fund readiness, and see your personal savings rate.

Rent vs Buy Calculator — True Cost Comparison

Compare the true total cost of renting vs buying over any time horizon. Includes opportunity cost of the down payment, equity buildup, home appreciation, rent inflation, and break-even year.

Paycheck Calculator — Net Pay & Tax Withholding

Calculate your exact take-home pay after federal income tax, FICA, state taxes, and pre-tax deductions like 401(k) and health insurance. Supports all 50 states and all filing statuses.

Home Affordability Calculator — Max Price & DTI

Find the maximum home price you can afford based on income, debts, and down payment using the 28/36 DTI rule and FHA 43% maximum. Includes PMI estimate and PITI breakdown.

Student Loan Calculator — Repayment Plans & PSLF

Compare all federal student loan repayment plans (Standard, Graduated, Extended, IBR, PAYE, SAVE) with full IDR calculations, PSLF tracker, and private refinancing comparison.

Mortgage Refinance Calculator — Break-Even & Savings

Calculate your monthly savings, break-even month, and cumulative net savings from refinancing. Supports rate-term and cash-out refinancing with closing cost analysis.

CD Calculator — APY, Compounding & Early Withdrawal

Calculate Certificate of Deposit returns with APY, compounding frequency, early withdrawal penalty, and inflation-adjusted real return. Includes a 5-rung CD ladder builder.

Capital Gains Tax Calculator — 2024 Federal & State

Calculate federal and state capital gains tax on investments using 2024 LTCG brackets, NIIT (IRC § 1411), and all 50 states. Includes tax-loss harvesting scenario and holding period analysis.

Car Lease vs Buy Calculator — True Cost Comparison

Compare the true cost of leasing vs buying a car. Calculates lease payment from money factor and residual, total cost over the term, and equity advantage of buying.

College Savings Calculator — 529 & Tuition Projection

Project 4-year college costs with tuition inflation, calculate 529 savings growth, and find the monthly contribution needed to cover 50%–100% of projected costs.

FIRE Calculator — Financial Independence Number

Calculate your FIRE number using the 4% safe withdrawal rate, find your months to financial independence, Coast FIRE number, and see how savings rate affects your timeline.

Dividend Calculator — DRIP Returns & Yield on Cost

Project dividend income with DRIP reinvestment, dividend growth rate, and price appreciation over time. Compare reinvesting vs. taking cash and see yield on cost by year.

Social Security Calculator — Claiming Age & Benefits

Estimate your Social Security benefit at 62, FRA, and 70 using the 2024 PIA formula with bend points. Find your break-even age, compare claiming strategies, and calculate spousal benefits.

RMD Calculator — Required Minimum Distribution 2024

Calculate your Required Minimum Distribution (RMD) using the IRS Uniform Lifetime Table (2022 update). Includes SECURE 2.0 rules, 10-year projection, and penalty for missed RMDs.

401(k) & Roth IRA Calculator

Compare traditional 401(k) and Roth IRA contributions side by side. Project tax-deferred vs. tax-free growth, estimate employer match impact, and find the breakeven tax rate to decide which account wins.

Bond Price Calculator — YTM, Duration & Convexity

Calculate bond price from yield to maturity, coupon rate, and maturity. Find YTM from price, compute Macaulay and modified duration, convexity, and accrued interest for clean vs dirty price.

Dollar-Cost Averaging Calculator — DCA Returns

Simulate dollar-cost averaging vs. lump-sum investing over any period. Compare average cost per share, total invested, portfolio value, and risk-adjusted returns across market scenarios.

Emergency Fund Calculator — Target & Savings Plan

Calculate your ideal emergency fund size based on monthly expenses, job stability, and household risk. Get a month-by-month savings plan and see how much interest you could earn in a HYSA.

Rental Property Calculator — Cap Rate & Cash Flow

Analyze rental property returns with cap rate, cash-on-cash return, gross rent multiplier, NOI, and projected 10-year equity. Compare financing scenarios and calculate the 50% and 1% rules.

Options Pricing Calculator — Black-Scholes & Greeks

Price European call and put options using the Black-Scholes model. Calculate all five Greeks (Delta, Gamma, Theta, Vega, Rho), implied volatility, intrinsic vs. time value, and breakeven price.

Credit Card Payoff Calculator — Debt-Free Date

Calculate exactly when you will pay off your credit card debt and how much interest you will pay. Compare minimum payments vs fixed amounts, model avalanche and snowball strategies, and see how extra payments save you money.

Amortization Calculator — Full Payment Schedule

Generate a complete month-by-month amortization schedule for any loan. See exactly how much principal and interest you pay each month, your remaining balance, and the total cost of the loan over its full term.

CAGR Calculator — Compound Annual Growth Rate

Calculate compound annual growth rate (CAGR) from a beginning value, ending value, and number of years. Reverse-solve for required end value or time horizon. Compare CAGR across multiple investments side by side.

Present Value Calculator — PV of Future Cash Flows

Calculate the present value of a future lump sum or annuity stream. Discount future money back to today using any rate. Compare PV of multiple cash flows and understand the time value of money with step-by-step working.

GCD & LCM Calculator — Up to 10 Numbers

Find the GCD and LCM of up to 10 integers using the Euclidean algorithm. Shows prime factorization, divisibility check, and full step-by-step working.

Prime Factorization Calculator

Find the prime factorization of any positive integer and check primality.

Factorial Calculator — n!, n!! & Derangements

Calculate standard factorial (n!), double factorial (n!!), and subfactorial (!n / derangements) with exact BigInt arithmetic, scientific notation, digit count, trailing zeros, Stirling approximation, and step-by-step working.

Fibonacci Calculator — F(n), Sequence & Check

Find any Fibonacci number F(n) with exact BigInt arithmetic up to F(10000), generate sequences with golden ratio convergence, and check whether any integer is a Fibonacci number using the algebraic 5n²±4 perfect-square test.

Prime Number Checker

Check if any number is prime using an optimized trial division algorithm. Also lists factors.

Perfect Number Checker

Check if a number is perfect, abundant, or deficient and find all its proper divisors.

Roman Numeral Converter

Convert between Arabic numbers and Roman numerals (I, V, X, L, C, D, M).

Number Sequence Calculator

Find the nth term of arithmetic, geometric, and other common sequences.

Digital Root Calculator

Calculate the digital root (iterated sum of digits), additive persistence, Harshad check, and multiplicative digital root for any integer up to 300 digits.

Velocity Calculator — Speed & Time

Calculate velocity, distance, or time using v = d/t.

Acceleration Calculator — Kinematic Equations

Solve for acceleration, final velocity, initial velocity, time, or displacement using the five kinematic equations. Includes g-force conversion and step-by-step working.

Force Calculator — Newton's Second Law F = ma

Calculate force, mass, or acceleration using Newton's Second Law (F = ma). Solve for any variable with multi-unit support (N, kN, lbf, kgf, kg, lb, slug), preset real-world scenarios, g-force output, and gravitational weight on seven Solar System bodies.

Projectile Motion Calculator

Calculate range, max height, time of flight, and trajectory.

Work & Energy Calculator

Calculate work done, kinetic energy, potential energy, and power.

Momentum Calculator — p=mv

Calculate momentum, impulse, and solve collision problems.

Ohm's Law Calculator — V=IR

Calculate voltage, current, resistance, or power using Ohm's law.

Wave Calculator — Wavelength & Frequency

Calculate wavelength, frequency, period, and wave speed.

Gravity Calculator — Free Fall, Force & Escape

Calculate free fall height, time, and velocity. Compute gravitational force with Newton's law. Find surface gravity and escape velocity for any planet. NASA planet data included.

Ideal Gas Law Calculator — PV=nRT

Solve PV = nRT for any unknown variable.

Friction Calculator — Static, Kinetic & Inclined Plane

Calculate static and kinetic friction forces, find the normal force or coefficient, and solve inclined plane problems. Includes 11 material presets with published μ values.

Pendulum Calculator — Period & Frequency

Calculate the period, frequency, and length of a simple pendulum.

Spring Constant Calculator — Hooke's Law

Calculate spring constant, force, or displacement using Hooke's law (F = kx).

Coulomb's Law Calculator — Electrostatic Force

Calculate electrostatic force, charge, or distance using Coulomb's Law F = kq₁q₂/r². Supports multiple units, dielectric media, and solve-for-any-variable mode.

Capacitance Calculator — Q=CV, Energy & RC Circuits

Calculate charge, voltage, energy stored, series/parallel equivalents, and RC time constants for capacitors. Multi-unit support with circuit diagrams.

Thermal Expansion Calculator

Calculate linear and volumetric thermal expansion of materials.

Pressure Calculator — P=F/A

Calculate pressure from force and area, convert pressure units, and compute fluid pressure.

Density Calculator — ρ = m/V, Mass & Volume

Calculate density, mass, or volume using ρ = m/V. Supports multi-unit inputs, 40+ material presets, specific gravity, buoyancy check, and full unit conversion table.

Decibel Calculator — dB, Power & Sound Level

Convert between decibels, power ratios, and amplitude ratios. Combine multiple sound sources, compute distance attenuation, and see NIOSH hearing safety limits with an SPL reference meter.

Doppler Effect Calculator — Sound & Light

Calculate observed frequency shift for sound and light using classical and relativistic Doppler formulas. Includes medium presets, direction toggles, semitone output, and redshift z.

Centripetal Force Calculator

Solve for centripetal force, mass, velocity, or radius for circular motion. Supports linear velocity, angular velocity, frequency, and period. Includes 5 real-world presets, g-force output, and circular motion diagram.

Torque Calculator — τ = rF sin(θ)

Calculate torque from force, distance, and angle of application.

Kinetic Energy Calculator — KE=½mv²

Calculate translational and rotational kinetic energy.

Potential Energy Calculator — PE=mgh

Calculate gravitational potential energy (mgh) and elastic potential energy (½kx²).

Snell's Law Calculator — Refraction

Calculate refraction angles and critical angles for light passing between media.

Lens Equation Calculator — Optics

Calculate focal length, object distance, image distance, and magnification for thin lenses.

Half-Life Calculator — Radioactive Decay

Calculate remaining quantity, time elapsed, half-life, and decay constant using the exponential decay formula. Supports 4 modes, decay table, and isotope reference.

Escape Velocity Calculator — Planets & Stars

Calculate escape velocity, orbital speed, surface gravity, Schwarzschild radius, and orbital period for any planet, star, or celestial body. Solve for velocity, mass, or radius with solar system presets.

Buoyancy Calculator — Archimedes

Calculate buoyant force using Archimedes' principle (F = ρVg). Determines float or sink status, fraction submerged, apparent weight, net force, and operating leverage across Earth, Moon, Mars, and Jupiter gravity. Includes fluid and material density presets.

Heat Transfer Calculator — Conduction, Convection & Radiation

Calculate heat transfer by Fourier conduction, Newton convection, Stefan-Boltzmann radiation, or Q=mcΔT sensible heat. Material presets, NIST constants, step-by-step working.

Electric Power Calculator — P=VI, V²/R & I²R

Calculate electric power from any two of voltage, current, and resistance. Includes energy consumption in kWh and electricity cost estimation with preset appliances.

Magnetic Force Calculator — Lorentz

Calculate the magnetic force on a moving charge (Lorentz force) F = qvB sin(θ).

Resistor Color Code Calculator

Decode 4-band and 5-band resistor color codes to find resistance and tolerance.

Blackbody Radiation Calculator

Calculate peak wavelength, total radiated power per unit area, photon energy, and Planck spectrum for any temperature and emissivity. Visual spectrum chart included.

Reynolds Number Calculator

Calculate the Reynolds number to determine laminar or turbulent fluid flow.

Electric Field Calculator — Point Charge & Plates

Calculate electric field strength from point charges (E = kQ/r²), parallel plates (E = V/d), and electrostatic force (F = qE) with unit conversion and air-breakdown indicator.

Sound Intensity Calculator — dB

Calculate sound intensity level in dB from intensity, and convert between intensity and dB.

Specific Gravity Calculator

Calculate specific gravity, relative density, and compare material density to water.

Wave Speed Calculator — v = fλ

Calculate wave speed, frequency, wavelength, or period using v = fλ. Supports sound, light, and all wave types across different media with unit conversion.

Kinematics Calculator — SUVAT Equations

Solve all five SUVAT kinematic equations for displacement, initial velocity, final velocity, acceleration, and time. Enter any three known values and instantly solve for the remaining two.

Energy Calculator — KE, PE, Thermal & Electrical

Calculate kinetic energy (½mv²), gravitational PE (mgh), elastic PE (½kx²), thermal energy (mcΔT), and electrical energy (Pt). Convert between energy forms and units.

Specific Heat Calculator — Q = mcΔT Calorimetry

Calculate heat energy (Q), mass (m), specific heat capacity (c), or temperature change (ΔT) using Q = mcΔT. Solve any unknown, includes a reference table of 30+ common substances, and supports calorimetry problems with heat exchange between objects.

Combined Gas Law Calculator — P₁V₁/T₁ = P₂V₂/T₂

Solve the combined gas law for any unknown pressure, volume, or temperature. Also handles Boyle's Law (constant T), Charles's Law (constant P), and Gay-Lussac's Law (constant V) as special cases. Supports all major pressure and volume units.

Matrix Determinant Calculator

Calculate the determinant of 2×2 and 3×3 matrices.

Matrix Multiplication Calculator

Multiply two matrices together with step-by-step dot products.

Vector Calculator — Dot & Cross Product

Add, subtract, find dot product, cross product, and magnitude of vectors.

Matrix Inverse Calculator

Calculate the inverse of a 2×2 or 3×3 matrix with step-by-step elimination.

Eigenvalue & Eigenvector Calculator — 2×2 & 3×3

Calculate eigenvalues and eigenvectors for 2×2 and 3×3 matrices. Shows characteristic polynomial, eigenvectors, diagonalization, matrix properties, and step-by-step working.

Matrix Transpose Calculator

Transpose matrices of any size by swapping rows and columns.

Matrix RREF Calculator

Reduce any matrix to Row Reduced Echelon Form (RREF) using Gauss-Jordan elimination. Shows pivot positions, rank, and step-by-step row operations.

Matrix Calculator — Add, Multiply & Invert

Perform matrix addition, subtraction, multiplication, transposition, and find the determinant and inverse for matrices up to 4×4. Step-by-step working shown for all operations.

Cross Product Calculator — 3D Vector a × b

Calculate the cross product of two 3D vectors, find the resulting vector's magnitude and unit vector, verify orthogonality to both inputs, and compute the area of the parallelogram they span. Full determinant working shown with angle between vectors.

Combination Calculator — nCr & n Choose r

Calculate C(n,r) combinations without repetition, C̄(n,r) with repetition, P(n,r) permutations, and nʳ — all in one tool. Supports BigInt exact arithmetic for large n, step-by-step working, Pascal's triangle, combination listing, and session persistence.

Permutation Calculator — nPr

Calculate the number of permutations where order matters.

Boolean Algebra Calculator

Evaluate Boolean expressions with AND, OR, NOT, XOR, NAND, NOR, XNOR, implication, and biconditional. Generates truth tables for up to 4 variables with SOP, POS canonical forms, Σm/ΠM notation, and equivalence checking.

Combinations with Repetition — Stars & Bars

Calculate multiset combinations C̄(n,r) = C(n+r−1,r) where repetition is allowed. Features stars & bars visualization, step-by-step working, multiset listing, all four combinatorial variants, BigInt exact arithmetic, and session persistence.

Pascal's Triangle Calculator

Generate Pascal's triangle up to any row and expand (a + b)ⁿ using the binomial theorem. Shows all coefficients and the full polynomial expansion.

Equation Graph Generator — Plot y = f(x)

Plot up to 3 simultaneous y = f(x) equations on a shared axis. Supports polynomials, trig, logs, exponentials, and more. Download as PNG or copy to clipboard.

Parametric Curve Grapher — x(t) y(t)

Plot parametric curves defined by x(t) and y(t) and download the graph as PNG.

Polar Graph Generator — r(θ)

Plot polar equations r(θ) including roses, spirals, and limaçons. Download as PNG.

Random Number Generator

Generate random integers or decimals within any range. Generate single or multiple numbers at once.

Random Password Generator

Generate strong, secure random passwords with custom length and character sets.

Dice Roller — D4 to D100 with Advantage

Roll any combination of dice including D4, D6, D8, D12, D20, D100, or fully custom sides. Supports advantage, disadvantage, drop-lowest, modifiers, probability distribution charts, and full roll history.

Random List Picker

Enter a list of items and randomly pick one or more. Perfect for decisions, giveaways, and selections.

Coin Flip Simulator — Heads or Tails Online

Free online coin flip simulator with animated flip, adjustable bias (0–100%), batch flipping up to 100,000 times, live statistics (z-score, chi-square, streak tracking), flip history grid, and session persistence. Demonstrates the law of large numbers in real time.

Random Color Generator — HEX, RGB

Generate random colors with HEX, RGB, and HSL values. Copy values instantly.

Lottery Number Generator

Generate random lottery numbers for Powerball, Mega Millions, or custom number ranges.

UUID Generator — UUID v4

Generate UUID v4 universally unique identifiers instantly. Generate single or bulk UUIDs.

Age Calculator — Exact Age, Milestones & Birthday Countdown

Calculate your exact age in years, months, days, hours, and minutes. Includes next birthday countdown, zodiac sign, Chinese zodiac, generation, and age milestones.

Date Difference Calculator — Days Between Two Dates

Calculate the exact number of calendar days, business days, weeks, months, and years between any two dates. Includes hours, minutes, seconds, leap year count, and inclusive/exclusive endpoint options.

Unix Timestamp Converter

Convert between Unix timestamps and human-readable dates. Supports seconds and milliseconds.

Day of Week Calculator — What Day Was Any Date?

Find the day of the week for any date — past, present, or future. Shows ISO week number, day of year, quarter, leap year status, zodiac sign, and a mini calendar view. Includes famous historical dates and day-offset shortcuts.

Work Hours Calculator — Time & Pay

Calculate total work hours between a start and end time, with optional break deductions.

Shift Schedule Creator — Automatic Shift Planner

Automatically generate weekly shift schedules for any team. Add workers, define shift types, set preferences and days-off constraints, then auto-generate a balanced calendar. Download as PDF or CSV.

Countdown Calculator — Days Until Any Event

Live countdown to any date with days, hours, minutes, seconds, progress bar, business days, and saved countdowns.

Time Duration Calculator

Add or subtract time durations. Convert hours, minutes, and seconds.

Business Days Calculator

Count working days between two dates, add or subtract business days to find deadlines, and run a countdown — with US & UK holiday presets, Mon–Fri/Sun–Thu/Mon–Sat work week options, and detailed breakdowns.

Time Zone Converter — World Clock & Meeting Planner

Convert times between any of 400+ time zones instantly. Compare multiple cities side by side, find the best meeting time across zones, and see DST change dates for every region.

Week Number Calculator — ISO Week & Year Calendar

Find the ISO week number for any date, list all weeks in a year, and calculate the date range for any given week. Supports ISO 8601 and US/North American week numbering conventions.

BMI Calculator — Body Mass Index & Healthy Weight

Calculate your BMI instantly with metric or imperial units. See your weight category, BMI Prime, Ponderal Index, healthy weight range, and personalised recommendations using WHO standards.

Calorie Calculator — TDEE & Weight Goals

Calculate daily calories using Mifflin-St Jeor, Harris-Benedict, or Katch-McArdle. Find your TDEE and set calorie targets for weight loss, maintenance, or muscle gain.

Body Fat Percentage Calculator — US Navy Method

Estimate body fat percentage using the US Navy circumference method. See lean mass, fat mass, body composition category, and a BMI-based comparison — in metric or imperial units.

Heart Rate Zone Calculator — 5 Training Zones

Calculate all 5 heart rate training zones using Max HR % or Karvonen method. Supports Standard, Tanaka, and Gellish formulas with visual zone bar chart.

Ideal Weight Calculator

Calculate ideal body weight using Devine, Robinson, Miller, and Hamwi formulas.

Water Intake Calculator — Hydration

Calculate your recommended daily water intake based on weight, activity level, and climate.

Running Pace Calculator

Calculate pace, speed, distance, or time for running, walking, and cycling activities.

Macronutrient Calculator — Macros

Calculate your daily protein, carbohydrate, and fat targets based on your TDEE and goals.

BMR Calculator — Basal Metabolic Rate & TDEE

Calculate your Basal Metabolic Rate (BMR) and Total Daily Energy Expenditure (TDEE) using Mifflin-St Jeor, Harris-Benedict, and Katch-McArdle formulas. Compare all three formulas and see daily calorie targets by goal.

Sleep Calculator — Best Bedtime

Calculate ideal bedtimes or wake-up times based on 90-minute sleep cycles. Find out when to sleep or wake to feel refreshed and avoid mid-cycle grogginess.

TDEE Calculator — Total Daily Energy Expenditure

Calculate your Total Daily Energy Expenditure (TDEE) with macro targets using the Mifflin-St Jeor, Harris-Benedict, and Katch-McArdle formulas. Set weight goals and see calorie targets for loss, maintenance, and gain.

Pregnancy Due Date Calculator — EDD & Milestones

Calculate your estimated due date from LMP, conception date, IVF transfer date, or ultrasound. Get week-by-week milestones, trimester dates, and key prenatal appointment windows.

Ovulation Calculator — Fertile Window & Cycle Tracking

Predict your fertile window and ovulation date from your cycle length and last period. Includes a 6-cycle fertility calendar, basal body temperature interpretation, and the LH surge timeline.

One-Rep Max Calculator — 1RM & Training Loads

Calculate your one-rep max using Epley, Brzycki, Lombardi, and O'Conner formulas. Get full training load percentages for 50–95% of 1RM and compare formulas to find your most accurate estimate.

Waist-to-Hip Ratio Calculator — WHR & Health Risk

Calculate your waist-to-hip ratio and see your WHO cardiovascular risk category. Includes waist-to-height ratio, a body shape comparison (apple vs. pear), and healthy range targets by sex and age.

VO2 Max Calculator — Fitness Level & Training Zones

Estimate VO2 max from a 1.5-mile run, Rockport walk test, resting heart rate, or submaximal cycle test. Get your fitness percentile, aerobic age, and five heart-rate training zones.

Caloric Deficit Calculator — Lose Weight Safely

Calculate the daily calorie deficit you need to reach your goal weight by a target date. Based on TDEE and BMR. Shows safe deficit ranges, recommended macro splits, estimated weekly loss, and how long to reach your goal at different deficit levels.

Calories Burned Calculator — 40+ Activities & MET

Calculate calories burned during any exercise or physical activity using MET values, body weight, and duration. Covers 40+ activities including running, cycling, swimming, weightlifting, and daily tasks. Compares net vs gross calories burned.

Lean Body Mass Calculator — LBM & Fat-Free Mass

Calculate lean body mass (LBM) using four clinical formulas: Boer, James, Hume, and Peters. Get fat mass, fat-free mass, skeletal muscle mass estimate, and ideal protein intake based on LBM. Used in medicine for drug dosing and fitness for muscle tracking.

Molar Mass Calculator — Molecular Weight

Calculate the molar mass of common chemical elements and simple compounds.

Molarity Calculator — M = n/V

Calculate molarity, moles, or volume of solutions using M = n/V formula.

pH Calculator — pH, pOH & Ions

Calculate pH, pOH, [H⁺], and [OH⁻] concentrations for acids and bases.

Dilution Calculator — C₁V₁=C₂V₂

Solve any variable in C₁V₁ = C₂V₂ and generate serial dilution tables. Supports M, mM, µM, mg/mL, ppm and more.

Stoichiometry Calculator — Moles & Grams

Convert between moles and grams using molar mass. Calculate mass from moles and vice versa.

Periodic Table — Interactive Element Reference

Explore the full periodic table with detailed element data including atomic number, mass, electron configuration, electronegativity, density, melting point, and category. Search by name, symbol, or atomic number.

Percent Yield Calculator — Actual vs Theoretical Yield

Calculate percent yield, theoretical yield, or actual yield for any chemical reaction. Enter grams or moles, and get step-by-step stoichiometry working showing mole conversions, limiting reagent identification, and yield analysis.

Limiting Reagent Calculator — Find Limiting Reactant

Find the limiting reagent, excess reactant, and theoretical yield for any balanced chemical reaction. Enter masses or moles of two reactants, and get complete stoichiometric working with mole ratios and yield calculations.

Empirical Formula Calculator — From Mass or Percent

Find the empirical formula and molecular formula from mass percentages or grams of each element. Enter up to 6 elements, and see step-by-step mole calculations, ratio simplification, and molecular formula determination from molar mass.

Significant Figures Calculator — Count, Round & Arithmetic

Count significant figures in any number, round to N sig figs, and perform addition, subtraction, multiplication, and division with automatic sig fig rules applied. Supports scientific notation and explains which rule was used.

Henderson-Hasselbalch Calculator — Buffer pH

Calculate buffer pH using the Henderson-Hasselbalch equation: pH = pKa + log([A⁻]/[HA]). Solve for pH, pKa, or the acid/base ratio. Includes buffer capacity, weak base support, and common buffer presets for acetate, phosphate, TRIS, HEPES, and bicarbonate.

Word Count Calculator

Count words, characters, sentences, paragraphs, and estimate reading time for any text.

Text Case Converter

Convert text to UPPERCASE, lowercase, Title Case, Sentence case, camelCase, or snake_case.

Base64 Encoder & Decoder

Encode text and files to Base64, decode Base64 strings, generate data URIs, and more. Supports URL-safe Base64, MIME line-wrap, and live processing.

Morse Code Converter

Convert text to Morse code and decode Morse code back to text.

ASCII & Unicode Value Calculator

Convert any character to ASCII decimal, hex, octal, binary, and UTF-8 bytes — or decode character codes back to text. Full ASCII table included.

Number to Words Converter

Convert any number (up to trillions) to its English word representation.

Reading Time Calculator — Words Per Minute Estimator

Estimate how long any text takes to read at average, fast, or slow reading speeds. Paste your text or enter word count, choose audience type, and get per-paragraph timing with speaking time comparison.

Bitwise Calculator — AND, OR, XOR

Perform bitwise AND, OR, XOR, NOT, left shift, and right shift on 8/16/32-bit integers. Interactive bit toggle panel, colour-coded bit grid, multi-base output, and common bit manipulation patterns.

Binary Arithmetic Calculator

Add, subtract, multiply, and divide binary numbers with long-form carry/borrow visualization, column-by-column step table, multi-base output, and overflow detection.

Two's Complement Calculator

Convert integers to two's complement binary representation and back.

RGB to HEX Color Converter

Convert colors between RGB, HEX, and HSL formats instantly.

IP Subnet Calculator — CIDR

Calculate subnet mask, network address, broadcast address, and usable hosts for any CIDR.

Floating Point Converter — IEEE 754 Binary

Convert any decimal to its IEEE 754 32-bit and 64-bit binary representation — coloured bit display, field breakdown, special value detection, and hex-to-float reverse conversion. Runs entirely in your browser using JavaScript typed arrays.

Bandwidth Calculator — File Transfer Time & Speed

Calculate file transfer time from file size and connection speed. Convert between all bandwidth units (Mbps, GB, TB), estimate download/upload time, and see how many devices a connection can support simultaneously.

Voltage Divider Calculator

Calculate output voltage from a resistor voltage divider circuit using Vout = Vin × R2/(R1+R2).

Gear Ratio Calculator — RPM, Torque & Trains

Calculate gear ratio, output RPM, torque multiplier, and speed change for simple gear pairs and multi-stage gear trains. Visual SVG diagram included.

Beam Deflection Calculator

Calculate maximum deflection and slope for cantilever, simply supported, and fixed-fixed beams with section presets, material library, and serviceability code checks.

Pipe Flow Calculator — Darcy-Weisbach

Calculate fluid flow rate, velocity, and pressure drop in pipes using the Darcy-Weisbach equation.

Power Factor Calculator — AC Circuit

Calculate power factor, real power, reactive power, and apparent power for AC circuits.

Resistor Series & Parallel Calculator

Calculate equivalent resistance for resistors in series, parallel, or mixed configurations. Add or remove resistors dynamically and see the result instantly.

Concrete & Cement Calculator

Calculate concrete volume for slabs, footings, walls, columns, and circular pads. Shows bags needed (25 kg, 40 kg, 60 lb, 80 lb), cubic yards, and optional cost estimate.

Wire Gauge Calculator — AWG, Current & Resistance

Look up AWG wire gauge specs: current-carrying capacity (ampacity), resistance per foot, voltage drop, and cross-sectional area. Calculate wire size from current load and find safe circuit wire length.

Battery Life Calculator — Runtime & Charge Cycles

Estimate battery runtime from capacity (mAh/Wh) and current draw. Calculate charge cycles to 80% capacity, find the right battery size for your device, and compare battery packs.