Lab tool
Molecular Weight Calculator
Enter a molecular formula exactly as it appears on a label or certificate. The result updates as you type, with the contribution of each element.
Results update as you type. Nothing is sent or stored.
Molar mass—
| Element | Atoms | Atomic weight | Mass | Share |
|---|
How the result is worked out
The formula is split into elements and counts, groups in round or square brackets are multiplied out, and hydrate parts after a dot (for example ·5H2O) are added with their multiplier. Each count is multiplied by the IUPAC standard atomic weight and summed.
Good to know
- Element symbols are case sensitive: Co is cobalt, CO is carbon monoxide.
- Write hydrates as CuSO4·5H2O, CuSO4.5H2O or CuSO4*5H2O.
- D and T are accepted for deuterium and tritium in labelled standards.
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