Grams to Moles Calculator Formula

Understand the math behind the grams to moles calculator. Each variable explained with a worked example.

Formulas Used

Moles

moles = grams / molar_mass

Variables

VariableDescriptionDefault
gramsMass(g)36.03
molar_massMolar Mass(g/mol)18.015

How It Works

How to Convert Grams to Moles

Formula

moles = mass (g) / molar mass (g/mol)

Worked Example

Convert 36.03 g of water to moles.

grams = 36.03molar_mass = 18.015
  1. 01moles = 36.03 / 18.015
  2. 02moles = 2.0 mol

Frequently Asked Questions

When would I need to convert grams to moles?

Stoichiometry calculations require moles. You weigh substances in grams but need moles to determine reaction ratios.

Can I convert grams to moles without molar mass?

No. Molar mass is required because different substances have different masses per mole.

What is a mole?

A mole is 6.022 × 10^23 particles (Avogadro's number). It is the SI unit for amount of substance.

Ready to run the numbers?

Open Grams to Moles Calculator