Dilution Calculator
Use C1V1 = C2V2 to find the stock volume, final concentration or final volume of a dilution, or work from a dilution factor. Shows how much solvent to add.
What this calculator does
Enter any three of initial concentration, stock volume, final concentration and final volume, and solve for the fourth. A second mode works from a dilution factor.
When you need it
Dilutions are among the most common jobs in a chemistry lab: making a working solution from a stock, preparing standards for a calibration curve, or lowering a concentration before a measurement.
Formulas
- C₁V₁ = C₂V₂
- dilution factor = C₁ ÷ C₂ = V₂ ÷ V₁
- solvent to add = V₂ − V₁
How to use it
- Choose which quantity is unknown.
- Enter the other three values; use the same unit for both volumes and for both concentrations.
- Read the result and how much solvent to add.
Worked example
How do you make 100 mL of 0.50 M solution from 2.0 M stock?
- V₁ = C₂V₂ ÷ C₁ = (0.50 M × 100 mL) ÷ 2.0 M = 25 mL
- Solvent to add = 100 mL − 25 mL = 75 mL
Answer
Measure 25 mL of the 2.0 M stock and add water to a final volume of 100 mL.
Common mistakes
- Adding V₂ of solvent instead of diluting up to the final volume V₂.
- Mixing mL and L in the same equation.
- Using C₁V₁ = C₂V₂ when the dilution also involves a reaction.
Related tools
Frequently asked questions
What is the dilution formula?
C₁V₁ = C₂V₂. The moles of solute stay the same before and after dilution, so concentration times volume is constant.
What is a dilution factor?
The ratio of the initial concentration to the final one. A 1:10 dilution has a factor of 10.
Do the units have to be liters?
No. Any volume unit works as long as both volumes use the same one.