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Mole Calculator

Find the amount of substance in moles from a sample's mass and its molar mass. Enter the mass in grams and either type the molar mass directly or enter a chemical formula to fill it automatically. The calculator also reports the number of particles using Avogadro's number.

Mass
g
Compound
Element
Chemical formula
Molar mass
g/mol

What Is a Mole?

A mole is the SI unit for the amount of substance. One mole contains exactly 6.02214076 × 10²³ particles (Avogadro's number) — atoms, molecules, ions, or formula units.

The number of moles equals the sample mass divided by the molar mass of the substance.

Formula

n = m ÷ M

where n = moles, m = mass (g), M = molar mass (g/mol)

Example: Moles in 18 g of water (M = 18.015 g/mol):

n = 18 ÷ 18.015 = 0.999 mol


See also