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Chemistry Avogadro Number Calculator

A simple calculator for calculating a substance's Avagadro's constant. It has the value 6.0221(30)+1023 mol-1 and expresses the number of elementary entities per mole of substance.



Avogadro's number(N)


  • Z = Number of atoms within the crystal unit cell
  • M = Average atomic mass
  • D = Density
  • V = Volume

Defination / Uses

Number 6.022 × 10^23 indicating the number of (atoms or molecules) in a mole of any substance is called Avogadro's.

Avogadro's number are used in chemistry when you need to work with very long numbers. i.e 3.35 x 10^19 H2O molecules in a 1mg snowflake.

The units of Avogadro's number is mol-1.

What you need to know about Avogadro's number

  • It is a number, like a dozen, and as such has no boundaries, Avogadro's number can be compared to the chemist's dozen.
  • It's a vast quantity, far larger than we can understand.
  • Its value can only be calculated with same precision as the number of atoms in a measurable weight of a substance. Because vast amounts of atoms can't be counted directly, scientists have devised a number of creative indirect measures involving motion and X-ray scattering.
  • Its practical implementation is confined to counting small items such as atoms, molecules, formula units, electrons, and photons.


The Avogadro constant was named after Amedeo Avogadro, an early nineteenth-century Italian scientist who proposed in 1811 that the volume of a gas (at a given pressure and temperature) is proportional to the number of atoms or molecules, regardless of the gas's nature.

Use the upper given formula for manual calculations. No sign-up, registration OR captcha is required to use this tool.