What is Dilution?
The Dilution Calculator uses the fundamental dilution equation C₁V₁ = C₂V₂ to determine how much stock solution you need to prepare a desired dilution. This is one of the most frequently used calculations in chemistry labs, biology labs, pharmacies, and clinical settings.
The principle is simple: the amount of solute (moles) stays the same before and after dilution — you are only adding more solvent to reduce the concentration. C₁V₁ (moles before) = C₂V₂ (moles after).
This works for any concentration unit (M, mM, %, mg/mL, etc.) as long as you use the SAME unit for both C₁ and C₂, and the same unit for V₁ and V₂.
Formula
C₁V₁ = C₂V₂
Solving for V₁ (volume of stock needed): V₁ = (C₂ × V₂) / C₁
Solvent to add = V₂ − V₁ Dilution Factor = C₁ / C₂
Example — Dilute 10M stock to make 100mL of 1M: V₁ = (1 × 100) / 10 = 10 mL of stock Solvent to add = 100 − 10 = 90 mL Dilution factor = 10× (or 1:10)
How to use this Dilution Calculator?
1. Enter the stock (original) concentration C₁. 2. Enter your desired final concentration C₂. 3. Enter the desired final volume V₂. 4. See how much stock to take (V₁), how much solvent to add, and the dilution factor.
Lab tip: Always add the stock solution to the solvent (not vice versa), especially with acids. For precise dilutions, use a volumetric flask.