Convert between moles and number of particles (atoms, molecules, ions) using Avogadro's constant: 6.02214076 × 10²³ mol⁻¹.

2.000 mol contains 1.2044 × 10²⁴ particles

Avogadro's constant: N_A = 6.02214076 × 10²³ mol⁻¹. Defined as the number of atoms in exactly 12 grams of carbon-12.

What is Avogadro's Number?

Avogadro's number (N_A) is a fundamental physical constant that represents the number of particles (atoms, molecules, ions, or other entities) in one mole of any substance. Its exact value, defined by the SI system since 2019, is:

N_A = 6.02214076 × 10²³ mol⁻¹

One mole is the amount of substance that contains exactly 6.02214076 × 10²³ elementary entities. This definition links the macroscopic world (grams, kilograms) to the microscopic world (atoms, molecules). The number was named after the Italian scientist Amedeo Avogadro (1776–1856), who first proposed that equal volumes of gases at the same temperature and pressure contain the same number of molecules.

Key applications:

• Chemistry — converting between mass, moles, and number of atoms/molecules
• Physics — calculating the number of particles in a gas
• Materials science — determining atomic density and crystal structures
• Biochemistry — counting molecules in biological systems

Use this calculator to quickly convert between moles and the actual number of particles for any substance.

How to Use This Calculator

1. Select conversion direction: Choose “Moles → Particles” to convert moles to number of particles, or “Particles → Moles” to convert particles to moles.
2. Enter value: Input the amount in moles or the number of particles (use scientific notation if needed, e.g., 6.022e23).
3. Calculate: Click the “Calculate” button or press Enter.
4. Swap: Use the “Swap Direction” button to quickly switch between conversion modes.
5. Reset: Use “Reset” to restore default values.
6. Interpretation: The result shows the converted value. For example, 2 moles of any substance contain approximately 1.2044 × 10²⁴ particles.