Molar Mass Calculator
Calculate the molar mass of a compound by entering how many atoms of each element it contains. The calculator sums the atomic masses and shows a detailed breakdown of each element's contribution in g/mol.
Molar mass is the mass of one mole of a substance, measured in grams per mole (g/mol). It connects the atomic scale to the lab scale, letting you convert between grams and moles.
How to Calculate Molar Mass
- Write the molecular formula (for example, C6H12O6 for glucose)
- Count the atoms of each element
- Multiply each count by the element's atomic mass
- Add them all up
Worked Example: Glucose (C6H12O6)
- Carbon: 6 x 12.011 = 72.066 g/mol
- Hydrogen: 12 x 1.008 = 12.096 g/mol
- Oxygen: 6 x 15.999 = 95.994 g/mol
- Total: 72.066 + 12.096 + 95.994 = 180.156 g/mol
How This Differs from Molecular Weight
The terms "molar mass" and "molecular weight" are often used interchangeably, but molar mass specifically has units of g/mol while molecular weight is technically dimensionless (a ratio relative to 1/12 of carbon-12). In practice, the numbers are the same.
Common Molar Masses
| Compound | Formula | Molar Mass |
|---|---|---|
| Water | H2O | 18.015 g/mol |
| Carbon Dioxide | CO2 | 44.010 g/mol |
| Table Salt | NaCl | 58.440 g/mol |
| Glucose | C6H12O6 | 180.156 g/mol |
| Sucrose | C12H22O11 | 342.297 g/mol |