Dilution Calculator
Use C₁V₁ = C₂V₂ to find how much stock solution to dilute to reach a target concentration and volume.
How it works
C₁ · V₁ = C₂ · V₂ · V₁ = C₂ · V₂ / C₁ · solvent to add = V₂ − V₁
When you dilute a solution the amount of solute stays the same — only the volume grows. That gives the dilution equation C₁V₁ = C₂V₂: the concentrated stock times its volume equals the dilute product times its volume. Rearranging finds the volume of stock to measure out; the rest of the final volume is solvent.
Worked example
To make 100 mL of 2 M from a 10 M stock: V₁ = (2 × 100) ÷ 10 = 20 mL of stock, topped up with 80 mL of solvent.
Sources: Dilution (equation) — Wikipedia
Frequently asked questions
Do the concentration units have to match?
Yes — C₁ and C₂ must use the same unit, because the equation relies on their ratio. The unit cancels out, so molarity, mg/mL or percent all work as long as both sides agree.
Why can I not make it more concentrated?
Dilution only adds solvent, which lowers concentration. If your target is above the stock strength the tool blocks it, because you would need to add solute or evaporate solvent instead.
What is the dilution factor?
It is how many times more dilute the final solution is, C₁ ÷ C₂. A 10 M stock taken to 2 M is a 5× dilution — one part stock to four parts solvent by volume.
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