Molar Mass Calculator

Molar mass of any chemical formula, with per-element breakdown.

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The molar mass of a compound is the mass of one mole of it, in grams per mole (g/mol). This calculator parses a chemical formula, sums the standard atomic weights of every atom, and shows the total with a per-element breakdown — for chemistry students and lab work.

How it works

The tool reads the formula left to right, recognising element symbols, subscript counts, and nested parentheses or brackets with multipliers (for example Ca(OH)2 or Al2(SO4)3). It multiplies each element’s count by its IUPAC 2021 conventional atomic weight — the values on a standard periodic table — and adds them up:

molar mass = Σ (count of element × atomic weight)

Write a hydrate such as CuSO4·5H2O as CuSO4(H2O)5 for an exact parse.

Example

For glucose, C6H12O6:

  • C: 6 × 12.011 = 72.066
  • H: 12 × 1.008 = 12.096
  • O: 6 × 15.999 = 95.994

Total = 180.156 g/mol.

ElementCountAtomic weightSubtotal
C612.01172.066
H121.00812.096
O615.99995.994

The formula is parsed entirely in your browser and nothing leaves your device.

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