Molar Mass Calculator

Calculate molar mass from atomic masses and the count of each element present.

About Molar Mass Calculator

Molar mass is the sum of every atomic mass in the formula. The defaults reproduce glucose at 180.16 g/mol, a useful check on the arithmetic. Molar mass is required for every conversion between the mass you can weigh and the moles a reaction actually consumes.

Formula

Molar Mass

M = Σ (atomic mass × number of atoms)

M: Molar mass in grams per mole, numerically equal to the formula mass in atomic mass units

Worked example

With the default values below, Molar Mass Calculator returns Molar Mass of 180.1560. Change any input above and every figure here is recalculated in your browser.

Inputs used

Atomic mass of element 1minimum 0 g/mol: 12.011 g/mol
Atoms of element 1minimum 0: 6
Atomic mass of element 2minimum 0 g/mol: 1.008 g/mol
Atoms of element 2minimum 0: 12
Atomic mass of element 3minimum 0 g/mol: 15.999 g/mol
Atoms of element 3minimum 0: 6

Results

Molar Mass: 180.1560 g/mol
Mass From Element 1: 72.0660 g/mol
Mass From Element 2: 12.0960 g/mol
Mass From Element 3: 95.9940 g/mol
Total Atoms per Formula Unit: 24

Step by step

1Values used
2Molar Mass
3Molar Mass= 180.1560 g/mol
4Mass From Element 1= 72.0660 g/mol
5Mass From Element 2= 12.0960 g/mol
6Mass From Element 3= 95.9940 g/mol
7Total Atoms per Formula Unit= 24

Assumptions and limits

The result is derived only from the 6 inputs listed above. Anything not among them is not part of the calculation.
In particular, this calculator does not take inflation, tax, fees or charges or compounding frequency into account.
Figures are rounded for display to 4 decimal places, so totals built from several rounded parts can differ slightly from the unrounded arithmetic.

How these calculators are built and tested is described on the Methodology page. If a figure looks wrong, please report it.

Frequently Asked Questions

How is Molar Mass calculated?

M = Σ (atomic mass × number of atoms) Molar mass is the sum of every atomic mass in the formula. The defaults reproduce glucose at 180.16 g/mol, a useful check on the arithmetic.

Why does Molar Mass matter?

Molar mass is required for every conversion between the mass you can weigh and the moles a reaction actually consumes.

What values do I need to enter?

This calculator takes 6 inputs: Atomic mass of element 1, Atoms of element 1, Atomic mass of element 2, Atoms of element 2, Atomic mass of element 3, Atoms of element 3. The pre-filled defaults are a realistic starting point — replace them with figures from your own environment for a result you can act on.