Solution Dilution Calculator
Fill in three of C₁, V₁, C₂ and V₂, and leave one blank.
This result is an estimate only. Double-check important figures before relying on them.
How it is calculated
- C₁ × V₁ = C₂ × V₂
- The calculator solves for the value you leave blank
- Solvent to add = final volume − stock volume
- Dilution factor = C₁ ÷ C₂
For molar concentrations, see the molarity calculator.
Worked example
Making 100 mL of a 2 M solution from a 10 M stock:
- V₁ = 2 × 100 ÷ 10 = 20 mL of stock
- Add 80 mL of solvent, a 5× dilution
Why your number may differ
Volumes of some liquids do not add exactly when mixed. Always add concentrated acid to water, never the other way round, and follow lab safety rules.
Frequently asked questions
What is the dilution formula?
C₁V₁ = C₂V₂. The amount of solute stays the same when you add solvent, so concentration times volume is equal before and after.
How much solvent do I add?
The solvent is the final volume minus the stock volume. To make 100 mL from 20 mL of stock, add 80 mL of solvent.
Do the units matter?
Use the same unit for both concentrations and the same unit for both volumes. The answers come out in those units.