Chemistry
Mole Calculator
Convert among mass, moles, and particle count using molar mass.
Free to use — no sign-up or login.
Primary result
Particles (when applicable)
Amortization schedule
| # | Date | Payment | Principal | Extra | Interest | Balance |
|---|---|---|---|---|---|---|
A mole is a count of particles linked to mass by molar mass, in grams per mole. The menu keeps only the fields that conversion uses.
Solution volumes belong on the dilution calculator. Atom counts by Z are on the proton and neutron pages.
Molar mass is not density
Molar mass says how many grams make one mole. Density says how many grams sit in one milliliter. Water’s molar mass is about 18.015 g/mol. Its density is about 1 g/mL. Those are different quantities.
Particles use Avogadro’s number
Particle count is moles times 6.02214076×10^23. That line stays in scientific notation. The mole or gram result is shown to three decimal places.
Worked example: 18 g of water
Choose mass to moles. Mass = 18 g and molar mass = 18.015 g/mol. Moles = 18 / 18.015 = 0.999 mol. The particle line is scientific notation, not a fixed integer.
\[ n = 18 / 18.015 \approx 0.999\ \mathrm{mol} \]
Frequently asked questions
Why do some fields disappear?
The menu shows mass and molar mass, or moles and molar mass, or particles. Unused inputs stay hidden.
Is 18.015 the density of water?
No. 18.015 g/mol is a molar mass. Density is mass per volume.
Why is the particle line scientific?
A mole is about 6.022×10^23 particles. A fixed decimal would be an unreadable string of digits.
What does moles to mass return?
Grams, equal to moles times molar mass, shown to three decimals.
Can I enter a zero mass?
No. Mass, moles, molar mass, and particles must be greater than zero.
References
Assumptions and limitations
Chemistry calculators are for study and illustration, not laboratory procedure or safety guidance. Confirm units, significant figures, and protocols from primary references before any practical work.
This page does not convert between volume and mass, and it does not look up molar masses. You supply the molar mass.