Free Molarity Calculator

Solve for molarity, moles, or volume given the other two.

Molarity (mol/L, often written M) is the standard unit for solution concentration in chemistry. If you know a compound's molecular weight, you can also convert between moles and grams (moles = grams / molecular weight) — pair this with our Molecular Weight Calculator for that conversion.

Worked Example

Example: Dissolving 2 moles of solute in 4 liters of solution gives a concentration of 2/4 = 0.5 M.

Formula / Method

Molarity (M) = Moles of Solute / Liters of Solution

Worked Example

Example: Dissolving 2 moles of solute in 4 liters of solution gives a concentration of 2/4 = 0.5 M.

Formula / Method

Molarity (M) = Moles of Solute / Liters of Solution