Physics Calculators
Classical mechanics, electricity and heat transfer — solve for any variable with automatic unit conversion.
Ohm's Law Calculator
V = I·R and electrical power
Newton's Second Law Calculator
F = m·a
Kinetic Energy Calculator
KE = ½·m·v²
Gravitational Potential Energy Calculator
PE = m·g·h
Hooke's Law Calculator
Spring force F = k·x
Coulomb's Law Calculator
Electrostatic force between two charges
Newton's Law of Universal Gravitation Calculator
F = G·m₁·m₂ / r²
Fourier's Law of Heat Conduction Calculator
Heat transfer rate through a wall
Density Calculator
ρ = m / V
Pressure Calculator
P = F / A
Physics laws covered
- Mechanics — Newton's second law, kinetic energy, potential energy, Hooke's law and universal gravitation.
- Electricity — Ohm's law and Coulomb's law.
- Heat transfer — Fourier's law of conduction, the heat-flow counterpart of Fick's diffusion law.
- Properties of matter — density and pressure.
Transport laws share one form
Fick's law (mass), Fourier's law (heat), Ohm's law (charge) and Darcy's law (fluid flow) all have the same structure: flux = −conductivity × gradient. Once you understand one, you understand them all. That is why this site places diffusion alongside the wider laws of physics and chemistry.
Physics laws at a glance
The key equations behind every physics calculator.
Ohm's Law
The current through a conductor is directly proportional to the voltage across it, with resistance as the constant of proportionality. (Georg Simon Ohm, 1827)
Open the Ohm's Law calculator →Newton's Second Law of Motion
The net force on a body equals its mass times its acceleration; equivalently, force equals the rate of change of momentum. (Isaac Newton, 1687)
Open the Newton's Second Law calculator →Kinetic Energy
The energy of motion of a body equals one half its mass times the square of its speed.
Open the Kinetic Energy calculator →Gravitational Potential Energy
Near a planet's surface, the potential energy gained by raising a mass equals its weight times the height raised.
Open the Gravitational Potential Energy calculator →Hooke's Law
The force needed to stretch or compress a spring is proportional to the displacement from its natural length. (Robert Hooke, 1678)
Open the Hooke's Law calculator →Coulomb's Law
The electrostatic force between two point charges is proportional to the product of the charges and inversely proportional to the square of the distance between them. (Charles-Augustin de Coulomb, 1785)
Open the Coulomb's Law calculator →Newton's Law of Universal Gravitation
Every mass attracts every other mass with a force proportional to the product of their masses and inversely proportional to the square of the distance between their centres. (Isaac Newton, 1687)
Open the Newton's Law of Universal Gravitation calculator →Fourier's Law of Heat Conduction
The rate of heat flow through a material is proportional to the negative temperature gradient and to the area through which heat flows. (Joseph Fourier, 1822)
Open the Fourier's Law of Heat Conduction calculator →Density
Density is mass per unit volume, an intrinsic property of a material at a given temperature and pressure.
Open the Density calculator →Pressure
Pressure is the force acting perpendicular to a surface divided by the area over which it acts.
Open the Pressure calculator →