Physics Calculators
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Looking for the equations and the numbers behind them? The physics constants and formula sheet lists every formula on this site with its calculator, plus CODATA 2022 values for c, g, G, h, R and the rest.
Mechanics
Newton's Second Law
Calculate force from mass and acceleration with Newton's second law, F = ma.
F = m × aAcceleration
Calculate acceleration from initial velocity, final velocity and time.
a = (v₁ − v₀) / tMomentum
Calculate momentum from mass and velocity (p = mv).
p = m × vProjectile Motion
Calculate the range, maximum height and flight time of a projectile from launch speed and angle.
R = v₀² · sin(2θ) / gFree Fall
Calculate free fall distance, time and impact speed from height.
t = √(2h/g), v = √(2gh)Torque
Calculate torque from force, lever arm length and angle.
τ = r × F × sin(θ)Terminal Velocity
Calculate terminal velocity from mass, drag coefficient, cross-sectional area and air density.
v = √(2mg / (ρ·A·Cd))Tension
Calculate the tension in a rope, cable or string holding or lifting a mass, with or without acceleration.
T = m × (g + a)Atwood Machine
Calculate the acceleration and rope tension of an Atwood machine — two masses over a frictionless pulley.
a = (m₁ − m₂)g / (m₁ + m₂), T = 2·m₁·m₂·g / (m₁ + m₂)Incline Tension
Calculate the rope tension needed to pull a block up a rough incline at steady speed.
T = m·g·(sin θ + μ·cos θ)Two-Rope Tension
Calculate the tension in each of two symmetric ropes or cables holding a hanging weight — a sign, lamp or load suspended from two anchors at an angle.
T = m·g / (2·sin θ)Impact Force
Calculate the average impact force of a collision from mass, impact speed and stopping distance.
F = m·v² / (2·d)Horizontal Projectile
Calculate the range, fall time and impact speed of a projectile launched horizontally from a height.
R = v·√(2h/g)Hooke's Law
Calculate spring force from stiffness and stretch using Hooke's law (F = kx), plus the elastic potential energy stored.
F = k × xEnergy
Kinetic Energy
Calculate kinetic energy in joules from mass and velocity (KE = ½mv²).
KE = ½ × m × v²Potential Energy
Calculate gravitational potential energy from mass and height (PE = mgh).
PE = m × g × hWork
Calculate mechanical work from force, distance and angle (W = Fd cos θ).
W = F × d × cos(θ)Power
Calculate power from work (energy) and time (P = W/t).
P = W / tWatts to Joules
Convert watts to joules: calculate energy in joules from power and time (E = P × t).
E = P × tElectricity & Waves
Ohm's Law
Calculate current and power from voltage and resistance with Ohm's law (V = IR, P = V²/R).
I = V / R, P = V² / RWavelength
Calculate wavelength from wave speed and frequency (λ = v/f) — for light, radio, WiFi and sound.
λ = v / fWatts to Amps
Convert watts to amps: calculate the current a device draws from its power and supply voltage (I = P / V).
I = P / VThermodynamics
Specific Heat
Calculate the heat energy needed to change a substance's temperature (Q = mcΔT).
Q = m × c × ΔTThermal Expansion
Calculate how much a material lengthens when heated (linear thermal expansion, ΔL = αL₀ΔT).
ΔL = α × L₀ × ΔTIdeal Gas Law
Solve the ideal gas law PV = nRT for pressure from amount, temperature and volume.
P = n·R·T / V