How It Works
This calculator works in 4 steps.
Enter the stock % v/v
Type the stock strength, such as 95% ethanol.
Enter the target % v/v
Type the target strength, such as 70%.
Enter the final volume
Type the volume of finished solution.
Read the component volume
The calculator returns V₁ and instructs a fill to the final volume, not a fixed water addition.
The Formula
The formula applies C₁V₁ = C₂V₂ with % v/v and a final volume measured after mixing.
%₁ × V₁ = %₂ × V₂% v/v = (mL component / mL solution) × 100V_diluent ≈ V₂ − V₁ (exceeded when liquids contract)- %₁ / %₂:
- Stock and target % v/v
- V₁:
- Component volume
- V₂:
- Final volume after mixing
To make 100 mL of 70% v/v ethanol from 95% ethanol, measure 73.7 mL of 95% ethanol and add water to the 100 mL mark. The water needed is more than 26.3 mL.
Conversion Table
The conversion table gives component volumes for 6 % v/v dilutions.
| Stock | Target | Final volume | Stock volume | Diluent step |
|---|---|---|---|---|
| 95% v/v | 70% v/v | 100 mL | 73.68 mL | Make to volume |
| 100% v/v | 10% v/v | 500 mL | 50 mL | Make to volume |
| 99.8% v/v | 50% v/v | 1,000 mL | 501 mL | Make to volume |
| 70% v/v | 35% v/v | 200 mL | 100 mL | Make to volume |
| 100% v/v | 0.1% v/v | 1,000 mL | 1 mL | Make to volume |
| 40% v/v | 5% v/v | 250 mL | 31.25 mL | Make to volume |
What Is the Volume/Volume Percent Dilution Calculator?
The Volume/Volume Percent Dilution Calculator is a tool that dilutes liquid-in-liquid solutions expressed as milliliters of component per 100 mL of final solution (% v/v). The calculator returns the volume of the concentrated liquid and directs the user to make up to the final volume.
Many liquid pairs shrink on mixing. Ethanol and water show the largest common effect: 52 mL ethanol plus 48 mL water gives about 96.3 mL, not 100 mL. % v/v is defined against the final volume, so the calculator states the make-to-volume step instead of a fixed diluent volume.
Common Uses
There are 5 main uses of this calculator.
Ethanol preparation
Labs make 70% v/v ethanol for surface disinfection and 80% v/v for DNA washes.
Solvent blends
Chemists prepare acetone, isopropanol, and methanol mixtures.
Glycerol stocks
Microbiologists make 50% v/v glycerol for freezer stocks.
HPLC mobile phases
Chromatographers prepare acetonitrile-water and methanol-water phases.
Fixatives
Histology labs dilute formaldehyde and alcohol fixatives.