Calculate the molar mass and molecular weight of any chemical formula instantly. Supports complex formulas with parentheses and hydrates. Free, accurate, and 100% client-side.
The molar mass (or molecular weight) of a compound is the sum of the atomic masses of all atoms in its chemical formula. This tool parses any valid chemical formula — including those with nested parentheses and hydrates — and calculates the total molar mass along with a detailed element-by-element breakdown. All calculations happen entirely in your browser; no data is sent to any server.
Molar mass is the mass of one mole of a substance, expressed in grams per mole (g/mol). It is calculated by summing the atomic masses of all atoms in a chemical formula. For example, the molar mass of water (H₂O) is approximately 18.015 g/mol.
Enter formulas using standard chemical notation. Use element symbols (H, C, O, Na, Fe, etc.) followed by numbers for atom counts. Use parentheses for groups, like Fe₂(SO₄)₃. For hydrates, use a dot like CuSO₄·5H₂O.
Yes! You can enter hydrate formulas using a dot separator, such as CuSO₄·5H₂O (copper(II) sulfate pentahydrate). The tool will correctly calculate the molar mass including the water molecules.
The tool supports all 118 elements of the periodic table, from Hydrogen (H) to Oganesson (Og), with standard atomic weights from IUPAC.
Yes, the calculator uses standard atomic weights from the IUPAC periodic table. Results are accurate to 3 decimal places, which is sufficient for most chemistry calculations.