Molarity Calculator

Use this free molarity calculator to find mol/L concentration from moles or from grams and molar mass.

All tools

Research-backed assumptions Formula steps Examples included Private in-browser use

Moles soluteVolume liters

Molarity0.5 M

0.5 mol / 1 L

Moles: 0.5 mol
Volume: 1 L
Molar mass: Entered moles directly

Use lab-safe procedures and measured final solution volume for real chemistry work.

Formula steps

Use the moles you entered directly.
Divide moles of solute by liters of solution.
Report the result as mol/L, commonly written as M.

How to use the molarity calculator

Choose moles and volume or grams and molar mass mode.
Enter liters of final solution volume.
Press Calculate molarity to see mol/L, written as M.
Use measured lab values, correct hydration state, and safety instructions for real chemistry.

Common uses

Calculate molarity from moles and liters.

Calculate moles from grams and molar mass first.

Check chemistry homework setup.

Use molecular weight output as a molar mass input.

Examples

Simple molarity 0.5 mol / 1 L

0.5 M

NaCl grams 58.44 g / 58.44 g/mol / 1 L

1 M

Dilute sample 0.25 mol / 0.5 L

0.5 M

Frequently asked questions

Plain-language answers about when to use the tool, what it does with your inputs, what to double-check, and how privacy works.

When should I use the Molarity Calculator?

Use it when your task matches one of these common needs: Calculate molarity from moles and liters. Calculate moles from grams and molar mass first. It works best when you already know the values, dates, units, or settings the page asks for.

What is the Molarity Calculator doing with my inputs?

In plain language: The calculator uses molarity = moles of solute / liters of solution. In grams mode, it first divides grams by molar mass to find moles. The examples on the page are there so you can compare your inputs with a filled-out calculation before copying the answer.

What should I double-check before trusting the answer?

Lab work needs correct significant figures, final solution volume, purity, hydration state, safety procedures, and teacher or lab instructions. Also check that you used the right unit, date, scale, or mode because small input changes can change the result.

Does the site save what I enter?

No. The calculator runs in your browser tab. Your recent answers stay only on the page while you use it, and they are not sent to a server.