Dilution calculator (C1V1 = C2V2)
How much stock solution to take to get the concentration you want.
How it works
C1 × V1 = C2 × V2 so V1 = C2 × V2 / C1. Solvent to add = V2 − V1. Dilution factor = C1 / C2.
Results are for guidance only and do not replace professional advice.
Worked example
With the default values:
- Stock concentration1
- Target concentration0.05
- Final volume wanted (mL)250
you get:
- Volume of stock to take12.5 mL
- Solvent (water) to add237.5 mL
- Dilution factor× 20 (1:20)
- Ratio5 % stock solution
Frequently asked questions
How does the “Dilution calculator” tool work?
C1 × V1 = C2 × V2 so V1 = C2 × V2 / C1. Solvent to add = V2 − V1. Dilution factor = C1 / C2.
What do I need to enter?
Just fill in: stock concentration, target concentration, final volume wanted. The result updates as you type.
Can you give an example?
Stock concentration: 1; Target concentration: 0.05; Final volume wanted (mL): 250 → Volume of stock to take: 12.5 mL; Solvent (water) to add: 237.5 mL.
Is this calculator free, and is my data private?
Yes. HOD Calc is completely free with no sign-up. The calculation runs in your browser: nothing you type is sent or stored.