Molar Mass Calculator

Enter a chemical formula (like C₆H₁₂O₆) or pick from the common compounds list, and this Molar Mass Calculator will give you the molar mass in g/mol alongside the compound's chemical formula and total atom count.

Use proper capitalization: H2O, NaCl, Ca(OH)2

Results

Molar Mass

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Chemical Formula

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Total Number of Atoms

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Elemental Composition by Mass

Results Table

Frequently Asked Questions

What is molar mass and how is it calculated?

Molar mass is the mass of one mole of a substance, expressed in grams per mole (g/mol). It's calculated by adding up the atomic masses of all atoms in a chemical formula, multiplied by their respective quantities.

How do I enter chemical formulas correctly?

Use proper capitalization for elements (H, O, Na, Cl) and include numbers for quantities. Examples: H2O for water, NaCl for salt, Ca(OH)2 for calcium hydroxide. Parentheses indicate groups that are repeated.

What's the difference between molecular weight and molar mass?

The terms are often used interchangeably. Molecular weight is the mass of a single molecule, while molar mass is the mass of one mole (6.022 × 10²³ molecules) of a substance. Both are expressed in g/mol.

Can I calculate molar mass for ionic compounds?

Yes, the calculator works for both molecular compounds (like H2O) and ionic compounds (like NaCl). The calculation method is the same - sum the atomic masses of all atoms present.

Why is molar mass important in chemistry?

Molar mass is essential for stoichiometry calculations, determining how much of each reactant is needed in chemical reactions, converting between grams and moles, and calculating concentrations of solutions.

How accurate are the atomic masses used?

The calculator uses standard atomic weights published by IUPAC (International Union of Pure and Applied Chemistry), which are the internationally accepted values for atomic masses.

Can I calculate molar mass for hydrates?

Yes, include the water molecules in your formula. For example, copper sulfate pentahydrate would be entered as CuSO4·5H2O or CuSO4*5H2O, and the calculator will include the mass of the water molecules.

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