Alcohol Proof Dilution Calculator

How to calculate spirit dilution?

The dilution calculation uses the conservation of alcohol mass principle to determine final volume.

Formula: Water to Add = (Initial Volume × Current ABV / Target ABV) - Initial Volume

Using the dilution calculator: an example

Scenario: Diluting 1000ml of 95% neutral grain spirit down to a standard 40% bottling strength.

Step-by-step calculation:

• Divide current ABV (95) by target ABV (40) to get the dilution ratio (2.375)
• Multiply the ratio by the initial volume (1000ml) to find total volume (2375ml)
• Subtract the initial volume to find water needed (1375ml)

Frequently Asked Questions

What kind of water should I use?

Distilled or demineralized water is best to prevent cloudiness (louching) caused by minerals in tap water.

Why does the spirit get warm when adding water?

Mixing ethanol and water is an exothermic reaction, meaning it releases a small amount of heat during the process.

What is the difference between ABV and Proof?

ABV is the percentage of alcohol by volume, while Proof is generally double the ABV (e.g., 40% ABV is 80 Proof).