Molecular Weight Calculator

Calculate the molecular weight (molar mass) of chemical compounds and molecules. Enter element symbols and their counts to get accurate molecular weight calculations.

Molecular Weight Calculator

About Molecular Weight

What is Molecular Weight?

Molecular weight (also called molar mass) is the sum of the atomic weights of all atoms in a molecule. It's expressed in grams per mole (g/mol) and is essential for stoichiometric calculations.

How to Use

  1. Enter the chemical symbol for each element
  2. Specify the number of atoms of each element
  3. Click Calculate to get the molecular weight
  4. Use the Add Element button for complex molecules

Common Examples

  • H₂O: Water - 18.015 g/mol
  • CO₂: Carbon dioxide - 44.009 g/mol
  • NaCl: Table salt - 58.443 g/mol
  • C₆H₁₂O₆: Glucose - 180.156 g/mol

Applications

  • Stoichiometric calculations
  • Solution preparation
  • Chemical reaction balancing
  • Laboratory experiments
  • Chemical analysis

Tips

  • Element symbols are case-sensitive (H, not h)
  • Use standard chemical notation
  • Count includes all atoms, including those in parentheses
  • For ions, the charge doesn't affect molecular weight