Science
Physics and chemistry calculators, from Ohm’s Law to molar mass.
Physics and chemistry calculators for the relationships that come up most in coursework and in practical work — Ohm’s Law, density, kinetic energy, half-life, molar mass and the rest.
Each one states the equation it applies and defines every symbol, so you can rearrange it by hand and check the result rather than take it on trust.
8 calculators in this category
Ohm's Law Calculator
Calculate voltage, current, resistance, and power (V=IR).
Density Calculator
Calculate density, mass, or volume using ρ = m/V.
Half-Life Calculator
Radioactive decay — find remaining quantity, time, or half-life.
Wavelength Calculator
Calculate wavelength, frequency, and wave speed (λ = c/f).
Kinetic Energy Calculator
Calculate kinetic energy, mass, or velocity (KE = ½mv²).
Force Calculator
Newton's Second Law: find force, mass, or acceleration (F=ma).
Gravitational Force Calculator
Newton's Law of Gravitation: F = Gm₁m₂/r².
Molar Mass Calculator
Calculate molar mass of any chemical formula with element breakdown.
Which calculator do I need?
Start from the job rather than the tool.
- Work with voltage, current and resistance — Ohm's Law Calculator
- Find density, mass or volume from the other two — Density Calculator
- Calculate a force from mass and acceleration — Force Calculator
- Find the gravitational attraction between two bodies — Gravitational Force Calculator
- Work out the energy of a moving object — Kinetic Energy Calculator
- Track radioactive or pharmacological decay — Half-Life Calculator
- Convert between wavelength, frequency and wave speed — Wavelength Calculator
- Find the molar mass of a compound — Molar Mass Calculator
What these calculators have in common
Assumptions worth knowing before you rely on any result here.
Mixed units are the most common source of a wrong answer
These formulas assume every input is in the same system. Entering mass in grams and volume in cubic metres produces a density a thousand times out, and nothing on screen will flag it. Convert first, then calculate.
Check the magnitude before the digits
Most errors are factors of ten rather than small slips. Knowing that water is 1 g/cm³, that household appliances draw hundreds of watts, and that visible light sits around 500 nm makes a wrong power of ten obvious immediately.
These are idealised relationships
Ohm’s Law holds for ohmic components at steady temperature; the kinetic energy formula ignores relativistic effects; gravitational force treats bodies as points. For everyday work the simplification is fine, but it is a simplification.