Last updated: June 2026
Use this dilution calculator to find the stock volume, final concentration, final volume or stock concentration for a simple dilution. It also includes dilution-factor and serial-dilution calculators.
- Use the Solution Dilution Calculator for c1V1 = c2V2.
- Choose the unknown quantity and enter the other three values.
- Keep both volumes in the same unit and both concentrations in the same unit.
- Use the Dilution Factor Calculator to find the fold dilution and solvent volume.
- Use the Serial Dilution Calculator for repeated dilutions using the same factor.
What is dilution?
Dilution is the process of making a solution less concentrated by adding solvent. The amount of solute in the transferred sample does not change, but that solute becomes distributed through a larger total volume.
Solution dilution formula
Here, c1 is the stock concentration, V1 is the stock volume transferred, c2 is the final concentration and V2 is the final solution volume.
The concentration units must match each other, and the volume units must match each other. The volume unit can be cm3, mL, dm3 or L because it cancels in the ratio.
Dilution factor
A dilution factor of 10 means that the final volume is ten times the transferred stock volume. The final concentration is therefore one-tenth of the stock concentration.
How much solvent should be added?
Final volume is not the same as solvent volume. To prepare 100 cm3 from 10.0 cm3 of stock, add enough solvent to reach 100 cm3; this corresponds to 90.0 cm3 of solvent if volumes are assumed additive.
Serial dilution
Serial dilution means repeating the same dilution in several steps. If every step has dilution factor D and the process is repeated n times:
Worked examples
Finding the stock volume
To prepare 250 cm3 of 0.100 mol dm−3 solution from 1.00 mol dm−3 stock:
Finding the dilution factor
Diluting 20.0 cm3 of stock to 200 cm3 gives:
Serial dilution
Three successive 10-fold dilutions of a 2.00 mol dm−3 solution give:
Common exam traps
Frequently asked questions
Can I use mL instead of cm³?
Yes. One millilitre is equal to one cubic centimetre. More generally, any volume unit works as long as both volumes use the same unit.
Can c₁ and c₂ use different concentration units?
No. Convert them to the same concentration unit before using the dilution equation.
Why does the amount of solute stay constant?
Dilution adds solvent but does not add or remove solute from the transferred stock sample.
Is dilution the same as neutralisation?
No. Dilution is a physical mixing process, while neutralisation is a chemical reaction between an acid and a base.