Chemistry calculator

Molarity Calculator

Calculate solution molarity from moles or from mass and molar mass.

Molarity

Moles of solute
Volume used
FormulaM = n ÷ V

What is molarity?

Molarity is a measure of concentration. It tells you how many moles of solute are present in one liter of solution.

Molarity formula using moles

M = n ÷ V

M is molarity in mol/L, n is the number of moles of solute, and V is the solution volume in liters.

Example using moles

Suppose a solution contains 0.5 moles of solute in 2 liters of solution.

M = 0.5 mol ÷ 2 L
M = 0.25 M

The solution therefore has a molarity of 0.25 mol/L, or 0.25 M.

Frequently asked questions

What units are used for molarity?

Molarity is typically expressed as moles per liter, written mol/L or simply M.

Do I need to convert milliliters to liters?

Yes. The standard molarity formula uses liters. Calquo automatically converts milliliters to liters when you select mL.

How do I calculate moles from grams?

Divide the mass of the solute in grams by its molar mass in grams per mole.

Moles = Mass ÷ Molar mass

What is molar mass?

Molar mass is the mass of one mole of a substance, usually expressed in grams per mole (g/mol).

Is molarity based on solution volume or solvent volume?

Molarity uses the total final volume of the solution, not just the volume of the solvent before the solute is added.