Science

Molarity Calculator

Moles, mass and concentration for any solution.

Enter your values

Results update instantly as you type — no submit needed.

Results
Molarity
1 mol/L
Moles of solute
1 mol
Millimolar
1000 mM
Mass percent (aqueous, approx)
5.844%

Working

  1. 1moles = 58.44 ÷ 58.44 = 1
  2. 2M = 1 ÷ 1 = 1

Quick answer

Molarity is moles of solute per litre of solution: M = mass ÷ (molar mass × litres).

M = mass ÷ (MW × V)

How to use the Molarity Calculator

  1. 1Enter the mass of solute in grams.
  2. 2Add the molecular weight.
  3. 3Enter the final solution volume in litres.

Frequently asked questions

Molarity vs molality?

Molarity uses litres of solution and changes with temperature; molality uses kilograms of solvent and does not.

How do I dilute a stock solution?

Use M₁V₁ = M₂V₂ — multiply the stock concentration by the volume taken and divide by the final volume.