Free Financial Math Calculators

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.