Calculator
Mass ↔ moles converter
Convert between grams and moles using molecular weight.
Moles
0.017218 mol
The formula: n = m / M
The number of moles n is the mass m in grams divided by the molar mass M in g/mol. Rearranged, m = n × M.
Worked examples
10 g of glucose (M = 180.16 g/mol) is 10 ÷ 180.16 = 0.0555 mol. 0.2 mol of sodium hydroxide (M = 40.00 g/mol) weighs 0.2 × 40.00 = 8.00 g.
Common mistakes
- Using milligrams with g/mol: convert mg to g first (or the answer is in millimoles).
- Using the anhydrous molar mass for a hydrate.
Learn the concept
FAQ
How do I convert mass to moles?
Divide the mass (in grams) by the molecular weight (g/mol). The result is in moles.
How do I convert moles to mass?
Multiply the moles by the molecular weight (g/mol). The result is in grams.
Where do I find the molecular weight?
On any Molekula product page (Identification tab), on CAS Common Chemistry, or on PubChem.