Dilution Calculator (C₁V₁ = C₂V₂)
Find how much stock solution and diluent to mix for a target concentration and volume, using the C1V1 = C2V2 dilution equation.
- Stock solution needed
- 50
- Diluent to add
- 450
- Dilution factor
- 1:10
How it works
This uses the standard dilution equation C₁V₁ = C₂V₂: the amount of solute (the concentrated substance) doesn't change when you add diluent, only the volume it's spread through does. Solved for the unknown, the stock volume needed is V₁ = (C₂ × V₂) ÷ C₁, and whatever's left of the target volume after that is diluent (usually water): diluent volume = V₂ − V₁.
Concentration and volume are treated as plain numbers rather than a fixed unit — enter concentration as %, mg/mL, mol/L, or any consistent scale, and volume as mL, L, or any consistent scale. Since the equation is a pure ratio, any matching pair of units gives the same proportionally correct answer, so there's no metric/imperial toggle to get right.
The desired concentration can never exceed the stock concentration — diluting a solution only ever lowers its concentration, never raises it, so that combination is rejected rather than returning a negative diluent volume.
FAQ
What if I want to make a stronger solution than my stock?
You can't — dilution only adds volume, which only ever lowers concentration. To reach a higher concentration than your current stock, you'd need to start from an even more concentrated source or reduce the volume (e.g. by evaporation), which is a different calculation than this one.
What does the 'dilution factor' mean?
It's the ratio of stock concentration to final concentration, shown as 1:N — a dilution factor of 1:10 means the final solution is one-tenth as concentrated as the stock, regardless of what units or actual volume you used.