Solution Dilution Calculator
Uses C₁V₁ = C₂V₂. Fill in any three values and leave the one you want to find blank.
Keep units consistent (e.g. concentrations both in mol/L, volumes both in mL).
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Solution dilution calculator (C₁V₁ = C₂V₂)
This dilution calculator solves the classic laboratory equation C₁V₁ = C₂V₂, which relates the concentration and volume of a stock solution to those of the diluted solution. Enter any three of the four values and leave the unknown blank — the calculator finds it instantly. It is essential for preparing solutions accurately in chemistry, biology, and medicine.
How the dilution equation works
The equation says the amount of solute stays the same before and after dilution: concentration × volume is constant. So if you know your stock concentration (C₁), your desired final concentration (C₂), and final volume (V₂), you can find the volume of stock needed (V₁ = C₂V₂ ÷ C₁), then top up with solvent to reach V₂. Just keep concentration units the same on both sides, and volume units the same on both sides.
A worked example
To make 100 mL of a 2 mol/L solution from a 10 mol/L stock: V₁ = (2 × 100) ÷ 10 = 20 mL. Measure 20 mL of stock and add solvent up to 100 mL. For molar mass and moles, use our molecular weight calculator and chemistry calculator.
Frequently asked questions
What units should I use?
Any, as long as they match. Concentrations might be mol/L, mg/mL, or % — just use the same unit for C₁ and C₂, and the same unit for V₁ and V₂.