Molar Mass Calculator
Calculate the molar mass of a chemical formula, with the mass percentage of each element.
About the Molar Mass Calculator
Type a chemical formula (case matters: Co is cobalt, CO is carbon monoxide; use brackets and · for hydrates). The calculator gives the molar mass and the count of each element.
Molar mass is the sum of the atomic weights of every atom in the formula, in grams per mole. Atomic weights here are the IUPAC Commission on Isotopic Abundances and Atomic Weights' abridged standard values. Molecular weight (in daltons) has the same number.
The formula
M = Σ (atoms of element × standard atomic weight)
Worked example
Glucose, C6H12O6
- 6 × 12.011 + 12 × 1.008 + 6 × 15.999
- = 180.156 g/mol
Questions people ask
Molar mass or molecular weight?
Numerically the same: g/mol vs daltons (u).
Why are some values rounded?
Isotope ratios vary in nature, so IUPAC gives abridged values to the precision that's meaningful.