Molar Mass Calculator

This molar mass calculator determines the molecular weight of any compound directly from its chemical formula, using standard IUPAC atomic weights. Molar mass, expressed in grams per mole (g/mol), is the bridge between the mass you can weigh on a balance and the number of molecules that chemistry equations are written in. Almost every quantitative chemistry calculation begins here: to find how many moles of a substance you have, you divide its mass in grams by its molar mass; to find how many grams you need of a given number of moles, you multiply. You type in the chemical formula using standard notation and the calculator adds up the atomic weight of every atom it contains. Element symbols must use correct capitalisation: a capital first letter and a lower-case second letter where applicable, such as Na for sodium, Cl for chlorine, or Mg for magnesium. Subscript numbers are written as ordinary digits, so water is H2O and glucose is C6H12O6. Brackets are fully supported for grouped units, meaning calcium hydroxide is Ca(OH)2 and aluminium sulfate is Al2(SO4)3. The built-in element table covers hydrogen through uranium and includes all elements commonly encountered in general, organic, and inorganic chemistry coursework. The result updates instantly as you type. Try H2O to get 18.02 g/mol, or C6H12O6 to get 180.16 g/mol, which are the two worked examples shown below. The calculator is intended for educational use and double-checking calculations; always verify critical values against authoritative sources for professional or laboratory work.

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Capitalise element symbols correctly: H, He, Li, Na, Cl, Ca, Fe, etc. Brackets are supported: Ca(OH)2, Al2(SO4)3. If the formula is invalid the result shows "check the formula".