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Mass ↔ amount of substance conversion

Mass to amount of substance, or the reverse, from the molar mass (n = m / M).

Parameters

Known quantities
Solute mass (m)
Molar mass (M)
Amount of substance (n)

Result

Awaiting the quantities required for the calculation.

Calculation, assumptions and sources

OverviewAmount of substance n from a mass and the molar mass, or the reverse (n = m / M).

Amount of substance n from a mass and the molar mass, or the reverse (n = m / M).

Method & formulasn = m / M
n = m / Mm = n × M

The amount of substance and the mass of a given sample are linked by its molar mass.

m
mass of the sample.
n
amount of substance, in moles.
M
molar mass of the compound, in g/mol.
Validity domainThe molar mass is that of the compound actually weighed: a hydrated salt (CuSO₄·5H₂O, for example) does not have the molar mass of its anhydrous form.

The molar mass is that of the compound actually weighed: a hydrated salt (CuSO₄·5H₂O, for example) does not have the molar mass of its anhydrous form. To relate n to a volume and a concentration (C = n / V), see the molarity calculator.

Example18.015 g of water (M = 18.015 g/mol) corresponds to 1 mol of water (n = m / M = 18.015 / 18.015).

18.015 g of water (M = 18.015 g/mol) corresponds to 1 mol of water (n = m / M = 18.015 / 18.015).