The Mole Converter

The mole ties three things together: the mass of a substance, how many moles that is, and how many actual particles. Type into any one box and watch the other two follow. The molar mass and Avogadro's number are the two bridges doing the work.

Mass

grams

Amount

moles

Particles

molecules

Type into any box — the other two update Molar mass converts mass ↔ moles Avogadro's number converts moles ↔ particles

The two bridges

Mass ↔ moles: divide a mass by the molar mass to get moles; multiply moles by the molar mass to get grams.

Moles ↔ particles: one mole is always 6.022×10²³ particles — Avogadro's number. Multiply moles by it to count particles; divide to go back.

This substance

Why the mole exists

Atoms are far too small and too many to count directly — even a teaspoon of water holds more molecules than there are stars in the sky. The mole is a counting unit, like a dozen but vastly bigger, that lets a mass you can weigh on a balance stand in for a number of particles you could never count.