Calculate the molar concentration of a solution from the mass of solute, its molar mass and the volume. Enter your values; the result updates as you type, with the method shown below.
About this calculator
Molarity is the number of moles of solute per litre of solution. This calculator gives the molarity, the amount of substance and the mass concentration from the mass, the molar mass and the volume.
Enter the mass of solute in grams, its molar mass in g/mol and the solution volume in litres.
When to use it
- Preparing lab solutions.
- Chemistry homework.
- Diluting stock solutions.
- Checking a recipe for a reagent.
How to read the result
C = n / V with n = m / M. 5.85 g of NaCl (58.44 g/mol) in 0.5 L gives 0.2 mol/L.
The volume is that of the final solution, not of the water added.
Mistakes to avoid
- Using the volume of water instead of the final solution.
- Using millilitres as litres.
- Taking the wrong molar mass (hydrates).
Formula
C = n / V, n = m / M
Worked example
5.85 g of NaCl (58.44 g/mol) in 0.5 L: 0.2 mol/L.
Frequently asked questions
What is molarity?
Moles of solute per litre of solution.
Where do I find the molar mass?
Add the atomic masses, or use our molar mass calculator.
What is the unit?
mol/L, often written M.
How do I dilute?
C₁V₁ = C₂V₂.
Where do I find the molar mass?
Use the molar mass calculator.
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Results are estimates for information only. Check important figures with a professional.