Avogadro's Number Calculator
Choose moles to particles, particles to moles, or sample mass to particles (with a molar mass you supply). The calculator uses the exact Avogadro constant, 6.02214076 × 10²³ per mole, and shows large numbers in scientific notation.
Last updated: September 26, 2026
Frequently asked questions
What is Avogadro's number?
The Avogadro constant, NA = 6.02214076 × 10²³ per mole, is the number of elementary entities in one mole of a substance. Its value is exact by the definition of the mole.
How do I convert moles to particles?
Multiply the amount in moles by NA. One mole of anything therefore contains 6.02214076 × 10²³ entities.
How do I convert grams to particles?
Divide the sample mass by the molar mass to get moles, then multiply by NA. Use the Molecular Weight Calculator if you need the molar mass of a formula.
Are the particles atoms or molecules?
It depends on what you choose to count. One mole of water contains NA molecules but 3 NA atoms. Ionic solids consist of formula units rather than molecules.
How do I type very large or small numbers?
Use e-notation, such as 6.02e23 or 1.5e-3. Results are shown in scientific notation.
How is this related to atomic mass?
Molar mass in g/mol is numerically equal to atomic or molecular mass in u. The Average Atomic Mass Calculator gives the mass of one atom in kg and g.