How to use the Molecular Weight Calculator
The molecular weight calculator adds up atomic masses for a chemical formula.
Open the Molecular Weight Calculator →
What you need to enter
- Formula (e.g. C6H12O6, Ca(OH)2)
The formula
Molar mass = Σ (atomic mass × number of atoms). Brackets multiply the atoms inside.
Worked example
Using the default values in the calculator:
- Formula (e.g. C6H12O6, Ca(OH)2): Ca(OH)2
| Molar mass | 74.092 g/mol |
| Composition | Ca 54.09% · O2 43.19% · H2 2.72% |
Tips for better results
- Use correct capitalisation, like NaCl.
- Check the formula before you enter it.
Common mistakes to avoid
- Writing co instead of Co or CO.
- Forgetting subscripts.
Please note: Results are estimates for general use. For safety-critical work such as electrical or building projects, check with a qualified professional and local codes. See our Disclaimer.