Is the mole calculator free?

Yes, it's completely free to use. No registration required.

What is a mole in chemistry?

A mole is the SI unit for the amount of substance. One mole contains exactly 6.022×10²³ elementary entities (Avogadro's number). It's like a 'dozen' but for atoms and molecules.

How do I calculate moles?

Moles = Mass (g) ÷ Molar Mass (g/mol). For example, 18g of water has a molar mass of 18 g/mol, so moles = 18 ÷ 18 = 1 mole.

What compounds are included?

Built-in compounds include H₂O, NaCl, CO₂, HCl, NaOH, H₂SO₄, C₂H₅OH, and many more. You can also enter a custom molar mass.

Free Online Mole Calculator - Convert Mass to Moles, Mole...

How to Use

Select a calculation mode: mass to moles, moles to mass, or moles to molecules
Choose a chemical compound or enter a custom molar mass
Enter the known value
Get instant results with moles, mass, and molecule count

The Mole Concept

The mole is the SI unit for measuring the amount of a substance. The core formula:

n = m / M

Where n = amount of substance (mol), m = mass (g), M = molar mass (g/mol)

Avogadro's Number: N_A = 6.022 × 10²³ mol⁻¹

Number of molecules = n × N_A

Frequently Asked Questions

Q: What is this mole calculator used for?

Perfect for chemistry homework, lab work, and exam preparation. Quickly convert between mass, moles, and number of molecules for any substance.

Q: Why does selecting a compound auto-fill the molar mass?

The tool has built-in molar masses for common compounds. You can still edit the molar mass manually for custom compounds.

Q: How many decimal places are shown?

Moles are shown to 4 decimal places, mass to 2 decimal places, and molecule count to 4 significant figures in scientific notation.

Q: Can I enter a custom compound?

Yes. Select "Custom" from the compound dropdown and enter the molar mass manually. This allows you to calculate for any substance.

Q: Does this tool upload my data?

No. All calculations happen locally in your browser. No data is uploaded to any server.

Q: What is Avogadro's number?

Avogadro's number is approximately 6.02214076×10²³ mol⁻¹. One mole of any substance contains this many elementary entities (atoms, molecules, or ions).

🧪 Mole Calculator

How to Use

The Mole Concept

Frequently Asked Questions