Stop hunting for the formula.
252 physics formulas with every symbol defined, 220 built-in calculators that solve them, and 27 constants - all free, no account, on any screen.
- No account, no sign-up
- Everything stays in your browser
- Built for a phone in a lecture
- 252Formulas
- 220Calculators
- 27Constants
- 14Unit groups
Formula of the day
A different equation every day - free, no account. Come back tomorrow for the next one.
Browse by category
Mechanics, heat, waves, fields, optics, relativity, quantum, and nuclear physics.
Mechanics
58 formulas across Kinematics, Dynamics, Work & Energy, and more
Thermodynamics
34 formulas across Heat & Temperature, First Law, Second Law, and more
Waves
37 formulas across Simple Harmonic Motion, Wave Properties, Sound Waves, and more
Electricity & Magnetism
48 formulas across Electrostatics, Electric Circuits, Capacitance, and more
Optics
34 formulas across Reflection, Refraction, Lenses, and more
Modern Physics
41 formulas across Special Relativity, Quantum Mechanics, Atomic Physics, and more
Reference tools
Web-native workflows for common physics lookup and calculation tasks.
Search everything
Find formulas by name, variable, concept, unit, or category.
Unit converter
Convert length, mass, time, pressure, energy, temperature, and more.
Physical constants
Reference universal, electromagnetic, atomic, thermal, and Earth constants.
Study guides
Free guides on memorizing formulas, solving kinematics, avoiding unit errors, and exam prep.
Popular formulas
Start with frequently used equations, then follow related formulas on each detail page.
Velocity is the rate of change of displacement with respect to time.
The net force equals mass times acceleration. Newton's fundamental law.
Energy possessed by an object due to its motion.
Ohm's Law for ohmic conductors.
Describes how light bends when passing between media with different refractive indices.
The most famous equation in physics. Mass and energy are equivalent and interconvertible.