The Physics of the Universe

Physics Calculators

Free, instant calculators for physics and astronomy. Each one lets you solve for any variable and shows the formula, a worked example and answers to common questions. Pick a tool below.

Mechanics & Motion

Kinetic EnergyEnergy of a moving object, KE = ½mv² MomentumLinear momentum, p = mv Work DoneWork by a force, W = F·d·cosθ Projectile MotionRange, max height and time of flight Free FallFall time and impact speed Terminal VelocityMax falling speed with air drag TorqueTurning effect of a force, τ = F·r·sinθ Moment of InertiaRotational inertia of common shapes Angular MomentumRotational momentum L = Iω Spring ConstantHooke's law stiffness, k = F/x Change in VelocityΔv from acceleration and time Force (F = ma)Newton's second law

Gravitation & Astronomy

Escape VelocitySpeed to escape a body's gravity Gravitational PEStored energy, PE = mgh Gravitational ForceNewton's law of gravitation Kepler's Third LawOrbital period vs. distance Weight on PlanetsYour weight across the solar system Drake EquationEstimate of alien civilisations Newton's Law of CoolingTemperature over time

Waves, Light & Electricity

Wave SpeedWave speed, v = fλ Frequency ↔ WavelengthConvert f and λ for light or sound Ohm's LawVoltage, current and resistance Voltage DropWire drop by length, size & material Coulomb's LawForce between electric charges CapacitanceCharge storage, C = Q/V DecibelPower/amplitude ratios to dB Photoelectric EffectPhoton energy and electron emission

Heat & Fluids

Specific HeatHeat energy, Q = mcΔT Ideal Gas LawPV = nRT Temperature ConverterKelvin, Celsius and Fahrenheit Bernoulli EquationPressure in a moving fluid

Quantum, Relativity & Modern

Half-LifeRadioactive decay over time Radioactive DecayExponential decay, N = N₀e^−λt Time DilationRelativistic clock slowing Uncertainty PrincipleHeisenberg position–momentum limit Quantum EntanglementEntangled-state relationships