Molecular Weight Calculator

Enter a chemical formula to calculate its molecular weight (molar mass). Supports elements (e.g., C, H, O) and parentheses (e.g., Mg(OH)2).

Result

--- g/mol

How it Works

This calculator parses the chemical formula you enter and sums up the atomic weights of all constituent elements based on their frequency in the molecule.

Examples

  • Water: H2O (2 Hydrogen, 1 Oxygen)
  • Glucose: C6H12O6 (6 Carbon, 12 Hydrogen, 6 Oxygen)
  • Magnesium Hydroxide: Mg(OH)2 (1 Magnesium, 2 Oxygen, 2 Hydrogen)

Atomic weights are based on the standard IUPAC periodic table values.

Quick FAQs

What is the difference between Molecular Weight and Molar Mass?
Molecular weight refers to the mass of a single molecule (in amu), while molar mass is the mass of one mole of that substance (in g/mol). Numerically, they are the same.
Does this support hydrates?
Yes, you can enter formulas like CuSO4(H2O)5. Just ensure all elements and numbers are correctly balanced.
Are atomic weights exact?
No, atomic weights are averages based on isotopic abundance on Earth. We use the most common IUPAC standard values.