Chemistry

Instant, private, and free

Mole Calculator.

Calculate moles from sample mass and molar mass.

On-device calculationNo signup
01

Set your values

Results update as you type.

Moles: 0.999167 mol

Moles

0.999167mol

Educational arithmetic only. Keep units consistent and use measured or explicitly supplied chemistry inputs; this tool does not infer reaction pathways, property tables, or safety guidance.

Use Cases

Chemistry homework and lab work

Quickly determine the number of moles in a given sample, essential for stoichiometry, preparing solutions, and understanding reactions.

Example: Calculate moles in 10 g of NaCl (molar mass 58.44 g/mol).

Recipe scaling in chemistry

When scaling a chemical reaction, convert masses to moles to maintain correct ratios.

Example: Scale a reaction from 0.5 moles to 2 moles by adjusting mass.

Frequently Asked Questions

How do I calculate moles using this calculator?
Enter the sample mass in grams and the molar mass in grams per mole (g/mol). The calculator divides the mass by the molar mass to give you the number of moles.
What is molar mass and where do I find it?
Molar mass is the mass of one mole of a substance, expressed in g/mol. You can find it on the periodic table for elements or by summing the atomic masses of all atoms in a compound's formula.
Can I use this calculator for any substance?
Yes, as long as you know the sample mass and the molar mass of the substance. It works for elements, compounds, and even mixtures if you use an average molar mass.

Tips & Common Mistakes

Tips

  • Ensure your mass is in grams and molar mass is in g/mol to get moles directly.
  • Use the periodic table to find accurate molar masses; for compounds, sum the atomic masses of all atoms.
  • Double-check your molar mass calculation for compounds with multiple atoms of the same element.
  • For quick estimates, round molar masses to whole numbers, but for precise work use exact values.

Common Mistakes to Avoid

  • Using mass in kilograms or milligrams without converting to grams first.
  • Confusing molar mass with molecular weight (they are numerically equal but units differ).
  • Forgetting to account for the number of atoms in a compound when calculating molar mass.

Last updated: August 13, 2026