Molar Mass Calculator
Enter a chemical formula to calculate its molar mass (molecular weight).
This tool is for informational and educational purposes only. It is not a substitute for professional financial, medical, legal, or engineering advice. See Terms of Service.
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Type a chemical formula using standard element symbols (e.g., H2O, NaCl, C6H12O6, Ca(OH)2). The calculator parses the formula, looks up atomic masses, and sums them to give the molar mass in g/mol. Parentheses and subscripts are supported.
About the Molar Mass Calculator
Molar mass is the foundation of stoichiometry. Knowing the mass of one mole of a substance allows you to convert between grams and moles, which is required for nearly every quantitative chemistry calculation. This calculator supports all common elements and handles parenthesized groups.
Frequently Asked Questions
What is molar mass?
Molar mass is the mass of one mole (6.022 x 10^23 particles) of a substance, expressed in grams per mole (g/mol). For water (H2O), the molar mass is 2(1.008) + 15.999 = 18.015 g/mol.
How do I enter chemical formulas?
Type element symbols with proper capitalization (uppercase first letter, lowercase second). Follow each element with its count if more than 1. Use parentheses for groups: Ca(OH)2, Mg3(PO4)2.
What is the difference between molar mass and molecular weight?
They are numerically the same but technically different. Molar mass has units of g/mol and refers to a mole of particles. Molecular weight (or relative molecular mass) is dimensionless and is the mass relative to 1/12 of carbon-12.