Alcohol Dilution Calculator — Water for Target ABV
CalculatorAn alcohol dilution calculator uses alcohol-volume conservation to estimate how much water is needed to lower a drink to a target ABV.
What is it
When diluting, the pure alcohol amount stays the same while total volume increases. Current volume times current ABV gives alcohol volume; dividing by target ABV gives final volume. This simple calculation does not model evaporation, volume contraction, or added beverage ingredients.
water to add = current volume × (current ABV ÷ target ABV − 1)
How to use
- 1Enter current volume and ABV.
- 2Enter a target ABV lower than the current ABV.
- 3Check water to add and final volume.
Reference
| Current | Target | Water |
|---|---|---|
| 360ml 16.5% | 12% | 135ml |
| 500ml 20% | 15% | 166.7ml |
Sources & standards
- MDN Web Docs: Client-side web APIs - MDN Web Docs
- Arithmetic operations - Wikipedia
FAQ
Can sparkling water or ice count as water?
A non-alcoholic liquid can be approximated the same way, but melting ice amount and sugar are separate.
What if target ABV is higher than current ABV?
Adding water cannot increase ABV. The target must be lower than the current ABV.
Is input sent to a server?
No. All calculations run only in your browser.