Molar Mass Calculator
Look up or enter molar mass for common compounds and elements.
PhD Chemistry (Analytical), MRSC
Analytical chemist with 12 years in pharmaceutical QA, spectroscopy, and solution chemistry. Passionate about making chemistry accessible.
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About the Molar Mass Calculator
Molar mass (also called molecular weight) is the mass of one mole of a substance, expressed in grams per mole (g/mol).
It equals the sum of the atomic masses of all atoms in the molecular formula. One mole contains 6.022 × 10²³ particles (Avogadro's number).
How it works
M = \sum (n_i \times A_i)
Tips to improve your result
- 1.
For ionic compounds, use the formula unit (e.g., NaCl) not the smallest ratio.
- 2.
Molar mass numerically equals relative molecular mass but has units of g/mol.