Alcohol By Volume Calculator - Mixture ABV and Proof Math

An alcohol by volume calculator turns a beverage's volume and ABV percent into the exact amount of pure alcohol it contains, then extends that result to mix-and-dilute math, US and UK proof, and alcohol by weight (ABW) so any drink's strength can be compared on the same scale.

• • Mix cocktails accurately: Combine a 40% spirit with juice, soda, or tonic and read the final ABV without any manual dilution math.
• • Dilute high-proof spirits: Plan how much water or juice to add to bring a cask-strength spirit down to a target bottling proof.
• • Compare bottles across regions: Convert ABV labels into US or UK proof to compare spirits labeled under different systems.
• • Track standard drink equivalents: Translate any pour into grams of pure alcohol to align with low-risk drinking guidelines.

Most home bartenders, brewers, and casual drinkers use ABV only as a label number. This calculator takes that label and turns it into the underlying physical quantity (pure ethanol in milliliters and grams) so you can compare, mix, or scale drinks without guessing.

The same tool handles single-beverage math, where you want to know how much pure alcohol is in a beer or wine pour, and mixture math, where two beverages of different strengths combine into one final ABV. Both modes use the same NIST ethanol density so the gram and milliliter answers stay consistent.

To plan drinks for a crowd using the per-guest standard drink math that pairs naturally with this calculator, see our Party Drink Calculator.

The calculator follows the volume-fraction definition of ABV used on every commercial label and in every spirits regulation worldwide, then adds the density-based step that converts pure alcohol volume into grams.

• V_beverage: Total volume of the alcoholic ingredient in milliliters.
• V_diluent: Volume of mixer, water, or low-proof ingredient in milliliters (zero for single-beverage math).
• ABV_beverage: Percent alcohol of the alcoholic ingredient.
• ABV_diluent: Percent alcohol of the second ingredient (zero for water, juice, or soda).
• ethanol_density: Density of pure ethanol, fixed at 0.789 g/mL at 20 C in line with NIST values.

Step one converts each ingredient's volume into pure alcohol volume by multiplying by ABV divided by 100. Step two sums those pure alcohol volumes and divides by the combined total volume to recover the final ABV percent. The same calculation handles one-beverage inputs by treating the diluent volume as zero.

Proof conversions then use the official factor from each country's regulator. US proof is exactly twice ABV, while UK proof is 1.75 times ABV, so a 40% ABV spirit is labeled 80 US proof or 70 UK proof on the same bottle.

According to NIAAA, a 12 fl oz (355 mL) US beer at 5% ABV contains about 14 g of pure alcohol, which equals one US standard drink.

When you need to convert fluid ounces, tablespoons, or cups into milliliters before entering them here, our Cooking Measurement Converter handles those unit swaps.

Four short definitions keep the math honest when you compare drinks, read labels, or scale recipes.

These four ideas show up in nearly every spirit and cocktail question. Keeping the volume-versus-mass distinction and the two proof systems straight prevents off-by-a-factor-of-two mistakes when you read international bottle labels.

If you are scaling a recipe that lists both milliliters and grams of alcohol, cross-check it with our Ingredient Volume to Weight Converter to avoid silent unit slip-ups.

Run through these steps whenever you mix, dilute, or compare a drink.

1. 1 Enter the alcoholic beverage volume: Type the milliliters of the spirit, wine, beer, or liqueur you are using. Leave the default 355 if you are working from a standard 12 fl oz US beer.
2. 2 Enter the beverage ABV: Type the percent from the bottle label. Beer typically sits between 4 and 6, wine between 11 and 14, and most spirits at 40.
3. 3 Add the mixer if applicable: Type the milliliters of juice, soda, tonic, or water you are combining with the spirit. Leave 0 for single-beverage math or to read pure alcohol grams only.
4. 4 Adjust the mixer ABV if it is not zero: Most mixers are 0% ABV, but fortified wines and aperitifs are not. Set this value when cutting one spirit with another.
5. 5 Read the final ABV, proof, and pure alcohol mass: The result panel reports the final ABV percent, US proof, UK proof, alcohol by weight, and the pure alcohol volume and mass that drive those numbers.
6. 6 Use the value to plan or compare: Match the final ABV to your cocktail target, compare bottles across proof systems, or divide the pure alcohol mass by 14 g to count US standard drinks.

To check a gin and tonic, enter 50 mL of 40% gin, leave the mixer volume at 150 mL of 0% tonic, and the result panel will show 10% final ABV, 20 US proof, 15.8 g of pure alcohol, and about 1.1 US standard drinks per glass.

When the final ABV drives a per-serving cost figure or a happy-hour pricing decision, pair it with our Recipe Cost Calculator.

Each output solves a real decision bartenders, distillers, and home cooks make every week.

• • Reliable cocktail dilution math: Replace mental arithmetic with a single ABV figure you can trust when scaling highballs, sours, and batched punches.
• • Direct proof conversions: Compare US proof, UK proof, ABV, and ABW on the same screen without consulting separate conversion charts.
• • Standard drink tracking: Read pure alcohol grams in one cell so you can compare any pour against low-risk drinking guidelines that use the 14 g US standard drink.
• • Distilling and bottling planning: Calculate how much water to add to bring a cask-strength spirit down to a target bottling proof before you mix the final batch.
• • Cooking and flambe calculations: Estimate how much alcohol remains after reduction when you deglaze a pan with wine or brandy, which matters for both flavor and safety.

Because every result is derived from the same NIST density constant, the gram and proof answers stay internally consistent, so you never have to wonder whether two columns on the same page disagree.

For non-alcoholic beverages that still need precise strength math, like espresso shots for a coffee menu, our Coffee Calculator covers the ratio side of the same kitchen workflow.

A few real-world variables move the ABV number beyond pure label math.

• • The calculator assumes ideal mixing between two components. Multi-ingredient cocktails with three or more liquids are still solvable by chaining the math but require manual volume additions.
• • ABV lab methods such as gas chromatography or near-infrared scanning can read 0.1 to 0.3 percentage points away from the simple volume-fraction estimate used here, which matters for compliance but not for bartending math.
• • The ethanol density is fixed at 20 C, so chilled drinks and frozen cocktails will show a slightly different pure alcohol mass than the calculator reports.

According to eCFR 27 CFR 30.11, US proof is defined as the ethyl alcohol content of a liquid at 60 degrees Fahrenheit, stated as exactly twice the percent of ethyl alcohol by volume.

According to NIST Chemistry WebBook, pure ethanol has a density of about 0.789 g/mL at 20 C, which converts pure alcohol volume into mass without losing precision.