Alcohol Dilution Calculator
Calculate water needed to dilute spirits to a target ABV/proof.
Water to Add
375.0 ml
Final Volume
1,125.0 ml
Proof
80
Dilution Details
| Water to Add | 375.0 ml |
| Final Volume | 1,125.0 ml |
| Target ABV | 40% |
| Proof | 80 |
| Dilution Ratio (spirit:water) | 1:0.50 |
Use distilled water for best results. The actual ABV may vary slightly due to volume contraction when mixing alcohol and water.
Use the Alcohol Dilution Calculator above to calculate your results. Enter your values and see instant results — all calculations run in your browser.
Disclaimer: This calculator is for informational purposes only and does not constitute tax, financial, or legal advice. Results are estimates based on the information you provide and current rates. Always consult a qualified tax professional or financial advisor for advice specific to your situation.
How It Works
Our Alcohol Dilution Calculator helps distillers, homebrewers, and cocktail enthusiasts accurately determine the amount of water needed to achieve a desired alcohol by volume (ABV) or proof. With the global spirits market projected to reach over $500 billion by 2026, precision in alcohol content is crucial for product consistency, legal compliance, and consumer satisfaction. Avoid over-dilution or under-dilution, ensuring your spirits meet market standards and personal preferences.
The calculation uses a simple mass balance equation: (Volume of Spirit * Initial ABV) = (Total Volume * Target ABV). This formula can be rearranged to solve for the volume of water needed by subtracting the initial spirit volume from the calculated total volume. Since alcohol and water do not mix perfectly additively due to volume contraction, this calculator uses a common industry approximation that is accurate for most practical dilution scenarios.
Always use distilled or demineralized water for dilution to prevent cloudiness or off-flavors caused by minerals. Remember that adding water can slightly reduce the overall flavor intensity, so taste as you go for smaller batches. A common mistake is not accounting for temperature differences, as alcohol volume can fluctuate with temperature, although this calculator assumes standard room temperature for simplicity.
Example: Diluting a High-Proof Whiskey for Bottling
- 1 You have 5 liters of a newly distilled whiskey at 75% ABV (150 proof) and want to dilute it to a bottling strength of 40% ABV (80 proof) for sale in the US market, where regulations are strict.
- 2 Using the formula: (5 Liters * 75% ABV) = (Total Volume * 40% ABV). Solving for Total Volume: Total Volume = (5 * 0.75) / 0.40 = 9.375 Liters. The amount of water needed is Total Volume - Initial Volume = 9.375 Liters - 5 Liters = 4.375 Liters of water.
- 3 You need to add approximately 4.375 liters of water to your 5 liters of 75% ABV whiskey to reach a final concentration of 40% ABV.
- 4 This precise dilution ensures your whiskey meets the standard bottling proof, preventing potential fines for mislabeling and providing a consistent product for consumers in a competitive market segment, especially as craft distilleries continue to grow in popularity through 2026.
Source: USDA · Last updated: April 2026
Frequently Asked Questions
How do I dilute spirits to a lower proof?
What is the difference between ABV and proof?
Does diluting alcohol change the taste?
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