Enter mass or moles, then click Calculate All.

Avogadro's number (Nₐ = 6.02214076 × 10²³ mol⁻¹) is the number of particles (atoms, molecules, ions, or electrons) in one mole of a substance. It serves as the fundamental conversion factor between the macroscopic scale (grams) and the microscopic scale (individual particles). The relationship is: particles = moles × Nₐ, moles = mass / molar mass, and mass = moles × molar mass. This constant is named after Amedeo Avogadro, who first proposed that equal volumes of gases contain the same number of molecules. The current exact value was established by CODATA and is fixed in the SI system since 2019. This calculator helps chemists, students, and researchers quickly convert between mass, moles, and particle count for any substance, using its molar mass. It is essential for stoichiometry, solution preparation, and understanding atomic-scale quantities.

1. Enter the Substance name (optional, for reference).
2. Enter the Molar Mass in g/mol (e.g., 18.015 for water).
3. Enter either Mass (g) or Moles (mol) – or both if known.
4. Click Calculate All to compute all related values.
5. The result shows mass, moles, number of particles, and the formulas used.
6. Click Reset to restore default example values.