What this calculator does
This combines the two conversions a mole sits between: particle count on one side and mass on the other. Two moles of water is 1.2×10²⁴ molecules and 36.04 grams.
The mole exists to connect those two. Particles are what react, in whole-number ratios set by the balanced equation, but mass is what a balance measures. The mole is the bridge, and the Avogadro constant and the molar mass are the two conversion factors that cross it.
The formula
The particle count is the amount multiplied by the Avogadro constant, 6.02214076×10²³ per mole, which has been exact by definition since 2019. The sample mass is the amount multiplied by the molar mass. The two outputs are independent of each other, each converting the same mole figure in a different direction.
| Term | Meaning |
|---|---|
| Avogadro constant | 6.02214076×10²³ per mole, exact by definition. |
| Molar mass | Grams per mole, which converts amount to mass. |
| Mole | The bridge between countable particles and weighable mass. |
| Formula unit | What the mole counts for an ionic compound, rather than a molecule. |
The inputs explained
| Field | What to enter |
|---|---|
| Amount of substance (mol) | Amount of substance in moles. |
| Molar mass (g/mol) | Molar mass in g/mol, used only for the sample mass output. |
When to use it
Converting a weighed sample
From grams to moles to particles, which is the standard chain in stoichiometry.
Checking a preparation
Confirming that a target number of moles corresponds to a sensible mass to weigh.
Teaching the mole concept
Seeing both conversions together makes the role of the mole clearer than either alone.
Worked examples
Every figure in the tables below is produced by this page’s own calculator at build time, so the numbers and the tool always agree. Select any row to load that scenario.
What does each amount give?
A range of amounts with particle counts and masses.
| Amount of substance | Number of particles | Sample mass | Amount of substance |
|---|---|---|---|
| 0.5 mol | 301,107,038,000,000,000,000,000 | 9.010 g | 0.5000 mol |
| 1 mol | 602,214,076,000,000,000,000,000 | 18.020 g | 1.000 mol |
| 2 mol | 1,204,428,152,000,000,000,000,000 | 36.040 g | 2.000 mol |
| 5 mol | 3,011,070,380,000,000,000,000,000 | 90.100 g | 5.000 mol |
Questions
What is the difference between this and moles to atoms?
This also reports the sample mass, using the molar mass. The particle count is identical. Use this one when you want both conversions at once, which is the usual case in a stoichiometry problem.
Why is the Avogadro constant exact now?
Because the 2019 SI redefinition fixed it by definition rather than deriving it from a mass measurement. The mole is now defined as exactly that many particles. The chosen value matched the previous experimental one, so nothing changed in practice.
Does the molar mass affect the particle count?
No. The particle count depends only on the amount in moles. The molar mass affects only the mass output. A mole of anything contains the same number of particles, which is the whole point of the unit.
What counts as a particle?
Whatever the mole refers to: atoms for an element, molecules for a molecular compound, formula units for an ionic one. A mole of sodium chloride is that many formula units, which is twice as many individual ions.
For the particle count alone, see the moles to atoms calculator. For converting a mass, see the grams to moles calculator.