Online physics calculator

This physics calculator brings together the formulas you use most in mechanics and electricity. Choose a formula — speed, acceleration, force, kinetic and potential energy, momentum, work, power, density, or Ohm’s law — enter your values, and get the answer in proper SI units. It is perfect for GCSE, A-level, and introductory college physics.

Formulas included

Motion: speed (v = d/t), acceleration (a = Δv/t), and momentum (p = mv). Forces and energy: Newton’s second law (F = ma), work (W = Fd), power (P = W/t), kinetic energy (½mv²), and gravitational potential energy (mgh). Materials and electricity: density (ρ = m/V) and Ohm’s law (V = IR). Each uses standard SI units, shown next to every input.

Tips for accurate answers

Always convert to SI units before calculating — metres, kilograms, seconds — or your result will be off. For example, convert grams to kilograms and centimetres to metres first. Use our unit converters to switch units quickly, and the scientific calculator for any extra arithmetic.

Frequently asked questions

What value of gravity should I use?

On Earth, use g = 9.81 m/s² (it is pre-filled). The Moon is about 1.62 m/s², and other planets differ.