Molar Mass from Chemical Formula Calculator

The molar mass of a substance is the mass of one mole of that compound, expressed in grams — a foundational value used in chemistry for stoichiometry, solution preparation, and unit conversions. Enter a chemical formula (such as H₂O, Al₂(SO₄)₃, or CuSO₄·5H₂O) into the Molar Mass Calculator and set your preferred decimal places to get the total molar mass in g/mol, along with the number of distinct elements and total atom count in the formula.

Enter a valid chemical formula (case sensitive). Supports parentheses and hydrates.

Number of decimal places in the result

Results

Total Molar Mass

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Number of Elements

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Total Atoms

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Results Table

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Frequently Asked Questions

How do I enter a chemical formula correctly?

Enter element symbols with proper capitalization (H, O, Ca, not h, o, ca). Use numbers as subscripts after elements (H2O, not H2o). For compounds with parentheses like Al2(SO4)3, include the parentheses and multiplier.

Can I calculate molar mass for hydrates?

Yes! Enter hydrates using a dot notation like CuSO4·5H2O or CuSO4.5H2O. The calculator will include the water molecules in the total molar mass calculation.

What atomic weights does the calculator use?

The calculator uses IUPAC standard atomic weights rounded to 3-4 significant figures. These are the same values typically found in chemistry textbooks and reference materials.

Why is molar mass important in chemistry?

Molar mass is essential for stoichiometry calculations, converting between grams and moles, determining empirical formulas, and calculating concentrations in solutions. It's a fundamental property for quantitative chemistry.

Can the calculator handle complex formulas with multiple parentheses?

Yes, the calculator can parse nested parentheses and complex formulas like Ca(OH)2 or Al2(SO4)3. Just ensure proper syntax with matching parentheses and correct element capitalization.

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

Molecular weight and molar mass are numerically the same but have different units. Molecular weight is dimensionless (relative to carbon-12), while molar mass has units of g/mol and represents the mass of one mole of substance.

How accurate are the calculated results?

Results are accurate to the precision of the atomic weights used (typically 3-4 significant figures). For most chemistry coursework and laboratory calculations, this precision is more than adequate.