Molar Mass Calculator
Calculate the molecular weight of chemical compounds with our precise molar mass calculator. Perfect for chemistry students, researchers, and professionals.
Supports parentheses, hydrates (·), and complex formulas
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Common
Organic
Salt
Acid
Mineral
Base
Hydrocarbon
Alcohol
Fertilizer
Molar Mass Calculator Results
Formula
H2O
Result
Note: Calculated on 1/29/2026 using standard atomic weights.
What is Molar Mass?
Molar mass is the mass of one mole of a substance (chemical element or chemical compound). It is expressed in grams per mole (g/mol) and is calculated by summing the atomic masses of all atoms in a molecule.
How to Calculate Molar Mass
- Identify all atoms in the chemical formula
- Find the atomic mass of each element from the periodic table
- Multiply each element's atomic mass by the number of atoms in the formula
- Sum all the individual masses to get the total molar mass
Examples
Water (H₂O)
2 Hydrogen atoms: 2 × 1.008 g/mol = 2.016 g/mol
1 Oxygen atom: 1 × 15.999 g/mol = 15.999 g/mol
Total: 18.015 g/mol
Glucose (C₆H₁₂O₆)
6 Carbon atoms: 6 × 12.011 g/mol = 72.066 g/mol
12 Hydrogen atoms: 12 × 1.008 g/mol = 12.096 g/mol
6 Oxygen atoms: 6 × 15.999 g/mol = 95.994 g/mol
Total: 180.156 g/mol
Common Applications
Stoichiometry
Calculating reactant and product quantities in chemical reactions
Solution Preparation
Determining mass needed for specific molar concentrations
Formula Determination
Finding empirical and molecular formulas from composition data