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Physics calculators

Physics calculators here cover motion and forces, energy, gravity and orbits, fluids and gases, heat and thermodynamics, waves, sound and optics, electricity and magnetism, and modern physics such as relativity, the photoelectric effect and radioactive decay. Each tool works in SI units, converts common alternatives and shows the equation used.

54 tools · Updated October 21, 2026

Showing 54 tools
Acceleration CalculatorMotion and forces0 to 100 km/h in 3 s9.25926 m/s²
Blackbody Radiation CalculatorHeat, thermodynamics and weatherPeak wavelength at 5,778 K501.5 nm
Buoyancy CalculatorFluids, pressure and gases1 L of ice (917 kg/m³) in water9.80665 N, floats
Capacitance CalculatorElectricity, magnetism and modern physics100 µF charged to 12 V1.2 mC
Centripetal Force CalculatorMotion and forces1,000 kg at 72 km/h on a 50 m curve8,000 N
Combined Gas Law CalculatorFluids, pressure and gases10 L, 1 atm, 25 °C → 50 kPa, −23.15 °CV₂ = 16.9923 L
Coulomb's Law Calculator, Electrostatic ForceElectricity, magnetism and modern physics1 µC and 1 µC, 1 m apart0.00898755 N, repel
Decibel CalculatorWaves, sound and light3 dB as a power ratio×1.9953
Density CalculatorFluids, pressure and gases540 g in 200 cm³2.7 g/cm³
Dew Point CalculatorMore physics tools25 °C air at 60% humidity16.7 °C (62.1 °F)
Doppler Effect CalculatorWaves, sound and light700 Hz source moving 30 m/s toward you767.093 Hz
Electric Field CalculatorElectricity, magnetism and modern physicsField 10 cm from a 1 µC charge898,755 N/C
Electric Power CalculatorElectricity, magnetism and modern physics120 V at 10 A1,200 W
Energy CalculatorEnergy, gravity and orbitsKinetic energy of 1,000 kg at 72 km/h200,000 J
Escape Velocity CalculatorEnergy, gravity and orbitsEscape velocity from Earth's surface11.1862 km/s
Force CalculatorMotion and forces1,000 kg accelerating at 3 m/s²3,000 N
Friction CalculatorMotion and forces60 N push on 10 kg, μₛ 0.5, μₖ 0.3Slides at 3.05801 m/s²
Gravity CalculatorEnergy, gravity and orbitsFall time from 20 m, no air resistance2.01962 s
Half-Life CalculatorElectricity, magnetism and modern physics100 after 11,460 yr, half-life 5,730 yr25 left
Heat Index CalculatorHeat, thermodynamics and weather90 °F at 60% relative humidityFeels like 100 °F
Heat Transfer CalculatorHeat, thermodynamics and weather10 m² of 100 mm insulation, ΔT 20 °C80 W
Ideal Gas Law CalculatorFluids, pressure and gases1 mol at 0 °C and 1 atm22.414 L
Kinematics CalculatorMotion and forces20 m/s to a stop at −5 m/s²40 m in 4 s
Kinetic Energy CalculatorEnergy, gravity and orbits1,000 kg moving at 72 km/h200,000 J
Lens Equation CalculatorWaves, sound and lightf = 10 cm lens, object at 30 cmImage at 15 cm
Mach Number CalculatorFluids, pressure and gases900 km/h at 11,000 m altitudeMach 0.8473, transonic
Magnetic Force CalculatorElectricity, magnetism and modern physicsProton at 1,000 km/s across 0.5 T8.0109 × 10⁻¹⁴ N
Momentum CalculatorMotion and forces1,000 kg at 20 m/s hits 1,500 kg at rest8 m/s together
Nuclear Binding Energy CalculatorElectricity, magnetism and modern physicsIron-56 binding energy per nucleon8.7903 MeV
Ohm's Law Calculator, V=IRElectricity, magnetism and modern physics9 V across 470 Ω19.1489 mA
Orbital Mechanics CalculatorEnergy, gravity and orbitsCircular orbit 420 km above Earth7.6613 km/s
Pendulum CalculatorMotion and forces1 m pendulum swinging 5°Period 2.00736 s
Photoelectric Effect CalculatorElectricity, magnetism and modern physics400 nm light on sodium (2.75 eV)0.3496 eV electrons
Potential Energy CalculatorEnergy, gravity and orbits10 kg lifted 5 m on Earth490.33 J
Pressure CalculatorFluids, pressure and gases500 N spread over 0.25 m²2,000 Pa
Projectile Motion CalculatorMotion and forces20 m/s at 45° from ground levelLands 40.789 m away
Resistor Color Code CalculatorElectricity, magnetism and modern physicsYellow, violet, red, gold bands4.7 kΩ ±5%
Reynolds Number CalculatorFluids, pressure and gasesWater at 1 m/s in a 5 cm pipeRe 49,831, turbulent
Snell's Law Calculator, RefractionWaves, sound and lightAir into crown glass at 30°θ₂ = 19.2529°
Sound Intensity CalculatorWaves, sound and light1 W source heard 10 m away89.01 dB
Special Relativity CalculatorElectricity, magnetism and modern physicsLorentz factor at 0.8cγ = 1.66667
Specific Gravity CalculatorFluids, pressure and gases7,850 kg/m³ against water at 4 °C7.8502, sinks
Specific Heat CalculatorHeat, thermodynamics and weatherHeat 1 kg of water by 80 °C334.72 kJ
Speed of Sound CalculatorMore physics toolsSpeed of sound in air at 20 °C343.2 m/s
Spring Constant CalculatorMotion and forces9.80665 N stretches a spring 5 cmk = 196.13 N/m
Thermal Expansion CalculatorHeat, thermodynamics and weather10 m of carbon steel warmed 40 °CGrows 4.8 mm
Thermodynamics CalculatorHeat, thermodynamics and weatherΔH −92.2 kJ, ΔS −198.7 J/K at 25 °CΔG = −32.958 kJ/mol
Tidal Force CalculatorEnergy, gravity and orbitsMoon's tidal pull at Earth's surface1.1 × 10⁻⁶ m/s²
Torque CalculatorMotion and forces50 N on a 30 cm wrench at 90°15 N·m
Velocity CalculatorMotion and forces100 m in 9.58 s37.578 km/h
Wave CalculatorWaves, sound and lightFrequency of 532 nm light563.52 THz, green
Wave Speed CalculatorWaves, sound and light440 Hz with a 78 cm wavelength343.2 m/s
Wind Chill CalculatorHeat, thermodynamics and weather0 °F with a 15 mph windFeels like −19 °F
Work & Energy CalculatorEnergy, gravity and orbits100 N pushing 10 m along the motion1,000 J of work

Which one do I need?

I know some of initial velocity, final velocity, acceleration, time and distance and need the restKinematics CalculatorI want the range, height and flight time of something launched at an angleProjectile Motion CalculatorI need force from mass and acceleration, or the reverseForce CalculatorI want kinetic, potential or other forms of energyEnergy CalculatorI need voltage, current or resistance from the other twoOhm's Law Calculator, V=IRI want the wavelength or frequency of a waveWave CalculatorI have a gas and need pressure, volume, temperature or molesIdeal Gas Law CalculatorI want to know how much of a radioactive sample remains after some timeHalf-Life Calculator

Motion, forces and energy

Mechanics problems usually start with kinematics, the description of motion. With constant acceleration, the five SUVAT equations link displacement, initial velocity, final velocity, acceleration and time, and any three known values give the other two. The Kinematics Calculator solves these directly, while the Projectile Motion Calculator splits motion into independent horizontal and vertical parts.

Newton's second law, F = ma, explains why motion changes. When forces are complicated or vary along a path, energy is often the easier route: work done equals the change in kinetic energy, and in the absence of friction, mechanical energy is conserved. Use the Energy or Work and Energy calculators for these, and the Momentum Calculator for collisions, where momentum is conserved even when energy is not.

Waves, sound and light

Every wave obeys v = fλ: speed equals frequency times wavelength. Sound in air at room temperature travels at about 343 m/s, while light in a vacuum travels at 299,792,458 m/s by definition. The Wave and Wave Speed calculators apply this relationship, and the Doppler Effect Calculator shows how motion shifts the observed frequency.

Sound levels use the logarithmic decibel scale, where every 10 dB increase means ten times the intensity. Optics tools cover refraction with Snell's law and image formation with the thin lens equation, which together explain prisms, eyeglasses and camera lenses.

Electricity, heat and modern physics

Ohm's law, V = IR, and the power relation P = VI cover most simple circuit questions; the Ohm's Law and Electric Power calculators solve for any missing value. Coulomb's law and the electric field calculator describe forces between charges, and the Magnetic Force Calculator handles moving charges in magnetic fields.

Heat calculations use Q = mcΔT for temperature changes and separate formulas for conduction, convection and radiation. At the smallest and fastest scales, classical formulas break down: the Photoelectric Effect Calculator shows light acting as particles, the Special Relativity Calculator shows time dilation at speeds near light, and the Half-Life Calculator models radioactive decay.

Questions people ask

The standard value is 9.80665 m/s², often rounded to 9.81 or 9.8 m/s². Actual gravity at Earth's surface varies slightly with latitude and altitude, but the standard value is accurate enough for nearly all coursework and everyday calculations.

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