🥃 Alcohol Dilution Calculator
Work out how much water to add to bring a spirit or infusion down from its starting alcohol percentage to a target percentage.
The dilution formula
Diluting alcohol follows the same basic conservation-of-mass principle used across chemistry and cooking: the total amount of pure alcohol stays the same before and after you add water, only the concentration (and total volume) changes.
This calculator uses the standard dilution equation C1 x V1 = C2 x V2, where C1 and V1 are your starting ABV percentage and volume, and C2 is your target ABV. Solving for the final volume (V2) and subtracting the starting volume gives the amount of water to add.
- Example: diluting 750 ml of 40% spirit down to 20% ABV requires doubling the total volume, meaning 750 ml of water added.
- This assumes water and alcohol volumes add linearly, which is a close approximation at typical beverage-alcohol strengths and is the standard method used in home bartending and food-safe infusions.
Provided for general recipe and hobby planning purposes — always dilute and serve alcohol responsibly and in line with local regulations.