Molarity Calculator

What the Molarity Calculator does

Molarity is moles of solute per litre of solution. The mass to weigh is molarity × volume × molar mass. For dilutions, the amount of solute stays the same, so C₁V₁ = C₂V₂ gives the volume of stock solution to use.

It also works as a solution concentration calculator or a dilution calculator.

Formula

• Mass (g) = molarity (mol/L) × volume (L) × molar mass (g/mol)
• Molarity = (mass ÷ molar mass) ÷ volume (L)
• C₁V₁ = C₂V₂, so V₁ = C₂V₂ ÷ C₁

Worked example

Using the starting values in the calculator above:

How to read the result

Dissolve the solute in less than the final volume, then top up to the mark; adding solute to the full volume overshoots it.

Use the molar mass of the exact form you have, including water of hydration (e.g. CuSO₄·5H₂O).

Check calculations and follow your laboratory’s safety procedures when preparing solutions.

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