Moles Calculator

Convert between mass, moles and number of particles for any substance.

About Moles Calculator

The mole links mass to particle count through Avogadro’s number. Dividing mass by molar mass gives moles, which is the currency of every stoichiometric calculation. Reactions happen in whole-number ratios of particles, not of mass, which is why converting to moles is always the first step.

Formula

Moles

n = m ÷ M; particles = n × 6.022 × 10²³

n: Amount of substance in moles
M: Molar mass in grams per mole

Worked example

With the default values below, Moles Calculator returns Amount of Substance of 0.427789. Change any input above and every figure here is recalculated in your browser.

Inputs used

Mass of substanceminimum 0 g: 25 g
Molar massminimum 0 g/mol: 58.44 g/mol

Results

Amount of Substance: 0.427789 mol
Number of Particles: 257,620,669,062,286,130,000,000
Amount of Substance: 427.7892 mmol
Mass per Mole: 58.4400 g
Mass Needed for Exactly One Mole: 58.4400 g

Step by step

1Values used
2Moles
3Amount of Substance= 0.427789 mol
4Number of Particles= 257,620,669,062,286,130,000,000
5Amount of Substance= 427.7892 mmol
6Mass per Mole= 58.4400 g
7Mass Needed for Exactly One Mole= 58.4400 g

Assumptions and limits

The result is derived only from the 2 inputs listed above. Anything not among them is not part of the calculation.
In particular, this calculator does not take inflation, tax, fees or charges or compounding frequency into account.
Figures are rounded for display to 6 decimal places, so totals built from several rounded parts can differ slightly from the unrounded arithmetic.

How these calculators are built and tested is described on the Methodology page. If a figure looks wrong, please report it.

Frequently Asked Questions

How is Moles calculated?

n = m ÷ M; particles = n × 6.022 × 10²³ The mole links mass to particle count through Avogadro’s number. Dividing mass by molar mass gives moles, which is the currency of every stoichiometric calculation.

Why does Moles matter?

Reactions happen in whole-number ratios of particles, not of mass, which is why converting to moles is always the first step.

What values do I need to enter?

This calculator takes 2 inputs: Mass of substance, Molar mass. The pre-filled defaults are a realistic starting point — replace them with figures from your own environment for a result you can act on.