Dilution Calculator
Enter any three of the stock concentration, stock volume, final concentration and final volume, and this calculator solves the dilution equation C1V1 = C2V2 for the missing value.
How to use the dilution calculator
- Enter the two concentrations and one volume you know.
- Leave the single unknown field blank.
- Read the missing value, solved from C1 x V1 = C2 x V2.
Examples
Volume of stock needed
C1 = 2 M, C2 = 0.5 M, V2 = 1 L
V1 = 0.25 L
Final concentration
C1 = 2 M, V1 = 0.25 L, V2 = 1 L
C2 = 0.5 M
Frequently asked questions
What is the dilution equation?
It is C1 x V1 = C2 x V2, where C1 and V1 are the stock concentration and volume, and C2 and V2 are the final concentration and volume.
How much stock solution do I need?
Rearrange to V1 = C2 x V2 / C1. Pipette that volume of stock, then add solvent up to the final volume V2.
What units should I use?
Any consistent units. Use the same concentration unit for C1 and C2, and the same volume unit for V1 and V2. The result keeps those units.
Does this work for serial dilutions?
Yes. Apply it one step at a time, using the previous step's final concentration as the next step's stock concentration.
Why can't the answer have two unknowns?
One equation can solve for only one unknown. You must supply three of the four values for a unique answer.
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