Molar Mass Calculator — M = m/n

Molar mass links the mass you can weigh on a balance to the amount in moles that chemical equations count. If you know how many grams a sample holds and how many moles that represents, this tool returns the molar mass in grams per mole — handy for identifying an unknown compound or checking a periodic-table sum.

Molar Mass Calculator — M = m/n

$M = \frac{m}{n}$

Solve for

Sample mass (m)

Unit

Amount (n)

Unit

Result unit

How to interpret the result

Worked check: 18.015 gram of water containing 1.000 mole gives M = 18.015 g/mol, matching the periodic-table sum (2×1.008 + 15.999). A result far from a whole-number pattern suggests an impure sample or a weighing error.

Assumptions

The sample is a single pure substance
Mass and amount refer to the same sample