What is the Mole Calculator?

The mole links the microscopic world (atoms and molecules) to measurable mass in the lab. One mole contains exactly Avogadro's number of particles and has a mass equal to the molar mass in grams. This calculator handles the three relationships chemists use daily: n = m / M for converting grams to moles, mass from moles, or solving for molar mass when you know both. Enter a formula to look up molar mass automatically, or type a value directly. Results include moles, grams, and particle count — all computed instantly in your browser.

How to use the Mole Calculator

1. Choose a mode: convert mass to moles, moles to mass, or find molar mass from mass and moles.
2. Enter a chemical formula (e.g. H2O) so molar mass is calculated automatically.
3. Or enter a molar mass manually if you already know it.
4. Fill in the mass (g) and/or moles (mol) depending on the selected mode.
5. Read moles, mass, molar mass, and particle count; copy the summary if needed.

Common use cases

• Converting 18 g of water to moles for a stoichiometry problem
• Finding how many grams 0.5 mol of NaCl weighs before weighing a sample
• Estimating particle count for a lab report

Frequently asked questions

What is the formula for moles?

n = m / M, where n is amount in moles, m is mass in grams, and M is molar mass in g/mol.

How many particles are in one mole?

One mole contains 6.02214076 × 10²³ particles (Avogadro's constant). This calculator multiplies your mole amount by that value.

Can I use this without a formula?

Yes. In mass ↔ mole modes, enter a molar mass directly in the override field instead of a chemical formula.