Science
Molar mass calculator
Chemical formula (H2O, C6H12O6…) → molar mass in g/mol.
- Instant
- Free
- Private (processed locally)
- No sign-up
Calculate a molar mass
Enter a chemical formula: the tool sums the atomic mass × atom count of each element and shows the total in g/mol, with a breakdown.
Accepted formulas
- Simple: H2O, NaCl, CO2
- With parentheses: Ca(OH)2, Al2(SO4)3
- Hydrates and chains: C6H12O6
- Brackets […] too
Examples
| Formula | Molar mass |
|---|---|
| H₂O | 18.015 g/mol |
| CO₂ | 44.009 g/mol |
| C₆H₁₂O₆ | 180.156 g/mol |
| Ca(OH)₂ | 74.092 g/mol |
Standard IUPAC atomic masses. 100% local calculation.
Frequently asked questions
What is the molar mass of water?
H2O = 2 × 1.008 + 15.999 = 18.015 g/mol.
Does the parser handle parentheses?
Yes: Ca(OH)2, Al2(SO4)3, etc. Brackets […] are also accepted.
Which atomic masses are used?
Standard IUPAC atomic masses, built in for all 118 elements.
Molar mass vs molecular weight?
Numerically identical: molar mass is in g/mol, molecular weight in u (amu).