🔬 Avogadro's Number Calculator
Translate between microscopic particle counts and macroscopic measurements using 6.022 x 10^23 mol^-1.
Enter the number of moles present in your sample.
Needed if you want the calculator to estimate mass.
Moles
1
Particles
6.022e+23
Uses Avogadro's number (6.02214076 x 10^23).
Mass (g)
18.015
Avogadro's constant links macroscopic amounts to discrete particles. For the computed moles above, the total number of entities is 6.022e+23 particles, which could refer to atoms, molecules, ions, or formula units depending on the substance.
How to Use This Calculator
Pick your conversion
Select whether you are starting from moles, particle count, or a measured mass. The input panel adjusts automatically.
Enter known values
Provide the numerical amount you have along with molar mass when mass-based conversions are involved.
Review the conversions
The calculator outputs moles, particle count, and (if possible) sample mass. Results display in scientific notation for extremely large or small numbers.
Use the summary
Copy the values directly into lab notebooks, stoichiometry problems, or mole ratio checkpoints.
Formula
N = n * N_A Â Â Â n = N / N_A
m = n * M = (N / N_A) * M
where N is the number of entities, n is moles, N_A is Avogadro's number, and M is molar mass (g/mol).
Example
12.0 g of carbon-12 has molar mass 12.0 g/mol, so n = 12.0 / 12.0 = 1.00 mol. Using Avogadro's number, N = 1.00 * 6.022 x 10^23 = 6.022 x 10^23 atoms.
Full Description
Avogadro's number, 6.02214076 x 10^23 mol^-1, bridges the gap between atomic-scale particles and measurable laboratory quantities. It is defined so that one mole of carbon-12 atoms contains exactly that many atoms and has a mass of 12 grams. This constant underpins the mole concept used in stoichiometry, analytical chemistry, and materials science.
The calculator automates common conversions: turning reported particle counts into moles for kinetic studies, estimating how many molecules are present in a weighed sample, or converting between microscopic counts and macroscopic masses. Including the molar mass lets you relate Avogadro-based estimates to real masses, yielding a complete picture for reaction planning and solution preparation.
Because the numbers involved are immense, the tool presents values in either conventional or scientific notation automatically. This avoids rounding errors and keeps results readable, whether you are dealing with zeptomole-scale single molecule experiments or bulk reagents.
Frequently Asked Questions
What counts as a "particle" in this calculator?
The term is generic. Depending on the context it could represent atoms, molecules, ions, electrons, photons, or formula units. Ensure the molar mass matches the entity being counted.
Do I need molar mass for every conversion?
No. Molar mass is only required when you want to connect particles or moles to a sample's mass. Pure mole-to-particle conversions rely solely on Avogadro's number.
Can I use scientific notation in the inputs?
Yes. Enter values like 3.5e21 or 6.022e23 to represent very large or small quantities without losing precision.
How precise are the results?
The calculator retains at least four significant figures and uses the official definition of Avogadro's constant, ensuring traceable, high-precision conversions.
Is temperature or pressure required?
No. Avogadro's number is independent of thermodynamic conditions. However, if you are working with gases, you may need the ideal gas law in addition to this tool to relate volume to moles.