Dilution Calculator
Work out any one value in a dilution — starting concentration, starting volume, final concentration, or final volume — using C₁V₁ = C₂V₂.
The formula
C₁V₁ = C₂V₂, where C₁ and V₁ are the concentration and volume of the starting (stock) solution, and C₂ and V₂ are the concentration and volume after dilution. Diluting doesn't change the total amount of solute — only the volume it's dissolved in — so this product stays constant.
Worked example
To dilute 10 mL of a 5 mol/L stock solution down to 1 mol/L: V₂ = (5 × 10) ÷ 1 = 50 mL. Since you already have 10 mL, add 40 mL of diluent (usually water) to reach exactly 50 mL total.
Frequently asked questions
Do the units of concentration matter?
No, as long as C₁ and C₂ use the same units (both mol/L, both %, etc.) — the formula works with any consistent concentration unit, and the same logic applies to volume units.
Can dilution increase concentration?
No — adding diluent only ever increases volume and decreases concentration. If you need a higher concentration, you need a different (stronger) stock solution or need to remove solvent, which this calculator doesn't model.