Molar Mass to Moles Calculator: Easily Convert Grams to Moles

If you’re doing chemistry calculations, converting grams to moles is something you’ll run into all the time. Whether you’re working on a lab report or solving a stoichiometry problem, the first step often involves figuring out how many moles of a substance you’re working with.

This guide will explain what moles are, how molar mass fits in, and how you can quickly calculate it with a free calculator.

🔢 Use the calculator below. Enter the mass and molar mass, and it’ll tell you how many moles you have.

🧪 What Is a Mole in Chemistry?

A mole is a basic unit in chemistry that represents a specific number of particles—typically atoms or molecules. That number is Avogadro’s number, which is:

1 mole = 6.022 × 10²³ particles

But instead of counting atoms (which are tiny!), we usually use mass in grams and convert it to moles using a substance’s molar mass.

⚖️ What Is Molar Mass?

Molar mass is the mass of one mole of a substance. It’s measured in grams per mole (g/mol).

For example:

• Carbon (C) has a molar mass of 12.01 g/mol
• Water (H₂O) has a molar mass of 18.02 g/mol
• Sodium chloride (NaCl) has a molar mass of 58.44 g/mol

You can find the molar mass of a compound by adding up the atomic masses of each element (using the periodic table).

🧮 Moles Formula

To calculate moles from grams, use this simple formula:

Moles = Mass (in grams) ÷ Molar Mass (g/mol)

✏️ Example: Converting Grams to Moles

Let’s say you have 36 grams of water (H₂O).

1. Molar Mass of H₂O = 18.02 g/mol
2. Mass = 36 g

Moles = 36 ÷ 18.02 ≈ 2 moles

So, you have 2 moles of water molecules.

🎯 Why Is This Important?

• Helps with stoichiometry in chemical reactions
• Essential for lab experiments and formulas
• Key to understanding chemical quantities

✅ Final Thoughts

Converting grams to moles is one of the most common calculations in chemistry—but now you know exactly how to do it. Use the formula, double-check your units, and try out our calculator to make it easier.