Moles to Grams Converter

Enter the molar mass (g/mol), then convert moles → grams or grams → moles instantly. Great for chemistry homework, lab prep, and quick stoichiometry checks.

Pick a preset or enter from periodic table.

Enter moles → get grams

Or enter grams → get moles

Result: grams (from moles)

Result: moles (from grams)

Quick tip

grams = moles × g/mol; moles = grams ÷ g/mol

Formulas used

grams = moles × molar_mass

moles = grams ÷ molar_mass

Molar mass is the mass of 1 mole of a substance. You get it by adding up the atomic masses in the chemical formula (in g/mol).

Common moles → grams examples

Substance Molar mass (g/mol) 1 mol → g 0.25 mol → g
Water (H₂O) 18.015 18.015 g 4.5038 g
Sodium chloride (NaCl) 58.44 58.44 g 14.61 g
Carbon dioxide (CO₂) 44.01 44.01 g 11.0025 g
Glucose (C₆H₁₂O₆) 180.16 180.16 g 45.04 g

Rounded values. Always use your lab’s molar mass if specified.

How to find the molar mass

Look at the formula, count atoms, multiply by atomic mass, then add. Example for H₂O:

  • 2 × H (1.008 g/mol) = 2.016
  • 1 × O (16.00 g/mol) = 16.00
  • Total = 18.016 ≈ 18.015 g/mol

Why moles matter

Moles let chemists count particles using mass. Stoichiometry is done in moles, not grams — so we move back and forth all the time.

FAQ

1. I got “—” as result

Make sure you entered a positive molar mass and at least one of moles or grams.

2. Can this do multi-step reactions?

No, this is a pure unit/concept converter. For reactions, convert each substance separately using its own molar mass and mole ratio.

3. Why don’t you fetch molar mass automatically?

Because many compounds have hydrates, isotopic labeling or mixtures. It’s best if you confirm the exact value from your source.