Atoms to Moles Calculator
Convert a particle count to moles, or moles to particles, using the SI Avogadro constant NA = 6.02214076×10²³ mol⁻¹. Works for atoms, molecules, or formula units.
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How to convert atoms and moles
- Enter moles or a particle count. Leave the other field blank.
- Use scientific notation in your head if needed; the page accepts ordinary decimals for the count field.
- Read moles, particle count, and the NA value used.
- The same constant applies whether you count atoms or molecules. The particle type is your interpretation.
Avogadro conversion
N = n × NA
| Avogadro constant NA | 6.02214076×10²³ mol⁻¹ (exact SI) |
|---|---|
| Mole | Amount of substance containing NA entities |
| Entity | Atom, molecule, ion, or formula unit |
| Formula | N = n × NA and n = N / NA |
| SI brochure | NA is fixed in the SI definition of the mole |
| Particle field | Labeled atoms on this page but accepts any entity count |
What this page converts
One mole contains exactly 6.02214076×10²³ specified entities. One mole of atoms is NA atoms. One mole of molecules is NA molecules. The default one mole therefore yields that particle count.
Atoms, molecules, and formula units
Atom means a single elemental particle. Molecule means a bonded covalent unit. Formula unit means the empirical ionic group such as NaCl. Avogadro's constant does not change among those labels; only your counting target does.
How N = n × NA is applied
Enter moles to multiply by NA. Enter a particle count to divide by NA. Both fields filled, or both blank, produce an error. Results show moles and the particle total with NA printed for audit.
Limits
Informational SI arithmetic. Not a particle detector or assay. See the disclaimer.