physics & chemistry

Science calculators

Physics and chemistry fundamentals — unit conversion, Ohm's law, density, force, energy, molar mass and pH.
18
calculators
SI
units throughout
free
no signup
Page 1 — physics & chemistry
Unit converter
Six categories of units, converted with exact factors.
Speed of light & sound calculator
Light vs sound over any distance — and the lightning trick.
Ohm's law calculator
Voltage, current, resistance and power — any two give the rest.
Density calculator
ρ = m/V solved for whichever one you're missing.
Force calculator (F = ma)
Newton's second law solved for any of its three variables.
Kinetic energy calculator
Energy of motion — and why doubling speed quadruples it.
Temperature converter
All four temperature scales from any one of them.
Molar mass calculator
Type a formula like Ca(OH)2 and get g/mol plus composition.
pH calculator
pH from concentration or concentration from pH — plus pOH.
science — page 2: applied science
9 more calculators →

The formulas behind the tools

Every calculator on this page implements a named, standard relationship: Ohm's law and the power law for circuits, F = ma, KE = ½mv², density as mass over volume, and the logarithmic definition of pH. The formula is displayed with each result, so the tools double as worked examples for homework.

Solve for any variable

Physics problems rarely ask for the same unknown twice, so the circuit, density, force and energy calculators let you choose which variable to solve for — enter the two you know and the third comes back, with the rearranged formula shown.

Chemistry from the formula

The molar mass calculator parses real chemical formulas — parentheses included, like Ca(OH)₂ — against standard atomic weights, returning the molar mass and the percentage composition by element. It's the first step of nearly every stoichiometry problem.

Units done properly

The general unit converter spans length, mass, temperature, pressure, energy and speed with exact conversion factors. Temperature is the special case — Celsius, Fahrenheit and Kelvin are offset scales, not simple multiples — and it's handled correctly.