Math
Moles to Grams Calculator
Convert moles to grams (or grams to moles) using molar mass. Built-in presets for water, NaCl, glucose, CO2, and more.
Moles to Grams Calculator
Convert moles into mass. Given moles and molar mass.
Picks a standard molar mass. Choose Custom to enter your own.
Amount of substance in moles.
Grams per mole of the substance.
Mass (g)
18.015
Moles (mol)
1
Mass (g)
18.015
Molar mass (g/mol)
18.015
Mass (kg)
0.018015
Millimoles (mmol)
1,000
Micromoles (umol)
1.0000e+6
Particles (N x Avogadro)
6.0221e+23
Frequently Asked Questions about the Moles to Grams Calculator
How do you convert moles to grams?
Multiply the number of moles by the substance molar mass in grams per mole: mass (g) = moles x molar mass (g/mol). For example, 2 mol of water with a molar mass of 18.015 g/mol weighs 36.03 g.
What is molar mass and where do I find it?
Molar mass is the mass of one mole of a substance, in grams per mole (g/mol). It equals the sum of the atomic masses of every atom in the chemical formula. The calculator ships with standard values for water, NaCl, CO2, glucose, ethanol, and other common substances.
How is moles related to Avogadro's number?
One mole contains exactly 6.02214076 x 10^23 elementary entities. So 1 mol of water is about 6.022 x 10^23 H2O molecules. The calculator shows particle count next to every result.
What is the difference between moles, millimoles, and micromoles?
Same quantity at different scales: 1 mole = 1,000 millimoles (mmol) = 1,000,000 micromoles (umol). Lab work and pharmacology often quote concentrations in mmol or umol because the numbers are easier to read.
Can I back-calculate molar mass from a sample?
Yes. Pick the Solve molar mass mode and enter the sample mass in grams and the amount in moles. The calculator returns molar mass = mass / moles.