Molar Mass Calculator
Type a chemical formula and get its molar mass in grams per mole, with a breakdown showing how much each element contributes. Parentheses and hydrate dots are supported.
How to calculate molar mass
- Enter a chemical formula, for example Ca(OH)2 or CuSO4.5H2O.
- Use parentheses for groups and a dot for water of crystallisation.
- Read the total molar mass in g/mol and the per element breakdown.
Examples
Water
H2O
18.015 g/mol
Sulfuric acid
H2SO4
98.072 g/mol
Glucose
C6H12O6
180.156 g/mol
Frequently asked questions
What is molar mass?
Molar mass is the mass of one mole of a substance, in grams per mole. It equals the sum of the standard atomic weights of every atom in the formula.
Is molar mass the same as molecular weight?
For molecules they are numerically the same. Molecular weight is dimensionless, while molar mass carries units of grams per mole.
Which atomic masses are used?
The IUPAC standard atomic weights, for example H 1.008, C 12.011, O 15.999, Na 22.990 and Cl 35.45. All 118 elements are included.
How do I enter hydrates and groups?
Use parentheses or brackets for repeated groups, such as Ca(OH)2, and a dot for hydrates, such as CuSO4.5H2O. Whitespace is ignored.
Why does my result differ slightly from another tool?
Atomic weights vary in the last decimal between sources and revisions. Small differences in the third decimal place are normal and expected.
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