Dilution Calculator
Solve any dilution using C₁V₁ = C₂V₂. Leave the field you want to find blank.
What is the Dilution Calculator?
The dilution calculator solves the dilution equation C₁V₁ = C₂V₂ for any one of the four variables. Whether you need to know how much solvent to add, what final concentration you will get, or how much stock solution to start with, this tool handles the math instantly. Dilutions are a fundamental laboratory procedure used to prepare working concentrations from concentrated stock solutions in chemistry, biology, and medicine.
How to Use the Dilution Calculator
- Fill in any three of the four fields: C₁, V₁, C₂, and V₂
- Leave the field you want to solve for blank
- Press Calculate to get the missing value
For example, to find the final volume needed to reach a target concentration, enter C₁, V₁, and C₂ and leave V₂ blank.
Dilution Formula
- C₁V₁ = C₂V₂
Where C₁ and V₁ are the concentration and volume of the stock solution, and C₂ and V₂ are the concentration and volume after dilution. The equation holds because dilution only adds solvent; the total amount of solute (C × V) stays constant.
Example Calculation
| Field | Value |
|---|---|
| Initial concentration (C₁) | 5.0 M |
| Initial volume (V₁) | 100 mL |
| Final concentration (C₂) | 1.0 M |
| Final volume (V₂) | 500 mL |
You would add 400 mL of solvent to your 100 mL of stock solution to reach 500 mL total at 1.0 M.
Why Dilute Solutions?
Stock solutions are kept concentrated because they are easier to store, more resistant to contamination, and take up less space. Diluting to a working concentration just before use ensures accurate, reproducible conditions. Serial dilutions are also used to create concentration gradients in experiments, prepare calibration standards, and test the sensitivity of assays. Correct dilution math prevents costly errors in the lab.
Common Uses of Dilution
- Preparing buffer solutions and media
- Creating standard curves for spectroscopy
- Adjusting reagent concentrations for titrations
- Making dilutions of pharmaceutical and chemical products
How the Dilution Calculator Works
The calculator applies the dilution equation C₁V₁ = C₂V₂. When you provide any three variables, it algebraically solves for the fourth by rearranging the equation — for example, V₂ = (C₁V₁) ÷ C₂. When the solved value is the final volume, the tool also shows how much solvent must be added (V₂ − V₁). The calculation runs locally in your browser for instant results and privacy.
Frequently Asked Questions
Can I mix units like mL and L?
As long as you use the same unit for both volumes (V₁ and V₂) and the same unit for both concentrations (C₁ and C₂), the equation works. Convert all values to consistent units first.
What does C₁V₁ = C₂V₂ actually mean?
It states that the amount of solute before dilution equals the amount after dilution, since dilution only adds solvent and never changes the total moles of solute.
What is a serial dilution?
A serial dilution is a sequence of stepwise dilutions where each step is diluted by the same factor, producing a geometric series of concentrations. It is often used to prepare calibration standards.