Alcohol Dilution Calculator
Use alcohol-volume conservation to estimate water addition and ideal final volume in mL, litres, fluid ounces, or US gallons.
Conserve the alcohol, change the total volume
Adding water does not intentionally change the amount of alcohol, so starting volume multiplied by starting ABV equals final volume multiplied by target ABV.
The water addition is the ideal final volume minus the starting volume. Real ethanol-water mixtures contract, so precision work needs measurement after mixing.
Measurement and safety
Alcohol strength varies with temperature, and dissolved sugar or other solids can obscure simple density readings.
Use potable water for beverages, add and mix carefully, and comply with local production, possession, and labeling rules.
Examples
Reduce 40% to 30%
Input
750 mL at 40% ABV; target 30% ABV
Show result
Result
Add about 250 mL water for an ideal final volume of 1,000 mL
Frequently Asked Questions
Can this increase alcohol strength?
No. Adding water can only reduce strength. Increasing ABV requires blending with a stronger known solution or another process.
Why might measured volume differ?
Ethanol and water do not combine with perfectly additive volumes, and temperature changes density.
References
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