Dilution Calculator (C₁V₁ = C₂V₂)

How to use this calculator

Enter the stock concentration, the final concentration and final volume. You get the volume of stock to use and how much solvent to add. Any concentration unit works as long as both are the same.

Formula

C₁ V₁ = C₂ V₂

Worked example

Make 200 mL of 0.5 M solution from a 10 M stock:

• V₁ = 0.5 × 200 ÷ 10 = 10 mL of stock
• Add 190 mL of water

Safety tip

When diluting strong acids, always add acid to water, slowly and with stirring — never water to acid.

Serial dilutions

For very large dilutions, dilute in steps (for example 1:10 four times for 1:10,000). Each step is more accurate than one huge dilution.

Frequently asked questions

What is the dilution formula?

C₁V₁ = C₂V₂ — the amount of solute stays the same, only the volume changes.

Which concentration units can I use?

Any, as long as C₁ and C₂ use the same unit — mol/L, %, mg/mL or ppm all work.

What is a dilution factor?

C₁ ÷ C₂. Diluting 10 M to 0.5 M is a 20-fold dilution.

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