Dilution calculator
C₁V₁ = C₂V₂. Leave the unknown blank.
Work it out
Fill in all but one. 4 boxes are empty, so there is more than one answer.
A worked example
You have 2 M hydrochloric acid and need 500 mL of 0.1 M.
25 mL of stock, made up to 500 mL
- 1V₁ = C₂V₂ / C₁ = (0.1 M × 0.500 L) / 2 M = 0.025 L.
- 2Measure 25 mL of the 2 M stock.
- 3Add solvent until the total volume is 500 mL — that is 475 mL of solvent, but measure the total, not the addition.
What this assumes
- Volumes are taken as additive. For concentrated solutions, and for mixing solvents, they are not — which is why a dilution is made up to a final volume rather than by adding a calculated amount of solvent.
- Always add concentrated acid to water, not water to acid.
The terms used here
- Stock solution
- A concentrated solution kept to be diluted as needed.
- Dilution factor
- How many times more dilute the result is: C₁/C₂, or equivalently V₂/V₁.
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This calculator runs in your browser. Nothing you type is sent anywhere, and no account is needed. If you want to go further than arithmetic — look a structure up, see what a reaction has been recorded as giving, or follow a mechanism — the library is open too.