ABV Calculator
Calculate ABV from beer gravity readings, a known percentage, or measured ethanol and final volume. Estimate ethanol mass, calories and U.S. 14-g drink equivalents.
ABV Calculator (Alcohol by Volume)
Table of Contents
How to Calculate ABV
Alcohol by volume (ABV) expresses the volume of ethanol in 100 volumes of a beverage. An ABV of 12% means 12 ml of ethanol per 100 ml of beverage. The reference volume basis is 20°C. This calculator estimates amounts from your inputs; it does not measure a sample.
Choose the Right Calculation Method
Known ABV: enter a percentage from 0 to 100 and the beverage volume in ml. Ethanol volume = beverage volume × ABV ÷ 100. Use this mode for a beverage whose ABV you already know, including wine or spirits.
Beer gravity estimate: ABV = (OG − FG) × 131.25. Enter specific gravity before and after fermentation, not a sugar percentage or an uncorrected Brix reading. The current fields accept OG from 1.000 to 1.200 and FG from 0.990 to 1.050, with OG greater than FG; those input bounds are not an accuracy guarantee.
Measured volumes: ABV = pure ethanol volume ÷ measured final beverage volume × 100. Both volumes must use ml; final volume must be positive and cannot be smaller than the ethanol volume. Measure the final mixture instead of adding ingredient volumes. This is not a calculator for combining several drinks with different ABVs.
Specific Gravity: Worked Example
Example: OG 1.050 and FG 1.010 give (1.050 − 1.010) × 131.25 = 5.25% estimated ABV. For 750 ml, that means 39.375 ml ethanol, displayed as 39.4 ml. Display rounding does not make the estimate more accurate.
U.S. Standard Drinks and Ethanol Calories
Example: 750 ml at 12% ABV contains 90 ml ethanol. Using the approximate density 0.789 g/ml gives 71.01 g, displayed as 71 g. Ethanol energy is 71.01 × 7 = 497.07 kcal, displayed as 497. This excludes energy from sugar and other ingredients.
The result uses the U.S. definition: 14 g of ethanol per standard drink. In the example, 71.01 ÷ 14 = 5.07, displayed as 5.1 U.S. equivalents. Definitions differ by country; this count is an amount comparison, not a personal safe-drinking limit or a blood-alcohol estimate.
Using Beer Gravity Readings
Record OG before fermentation and FG after fermentation, before priming sugar is added. Enter both as dimensionless readings such as 1.050. Use a decimal point in the fields. Keep the measurement conditions and calibration with your brewing notes so the estimate can be checked later.
Use hydrometer readings corrected to the instrument's calibration temperature. Alcohol changes refractometer readings after fermentation: raw refractometer values need an appropriate alcohol correction and instrument calibration before conversion to specific gravity. This calculator performs neither correction.
Accuracy, Limits and Sources
The 131.25 coefficient is a simple beer-brewing estimate; stronger beers and other beverage types can require different methods. No fixed error margin is promised. Approximate ethanol density, input measurement and display rounding also limit the mass and calorie results. This tool does not confirm fermentation completion, certify a commercial label or classify a beverage as alcohol-free.
Sources checked on 29 September 2026. The JRC brief was updated on 6 February 2026; the linked NIAAA and Brewer's Friend pages are undated.
Frequently Asked Questions
What does the gravity result mean?
Beer gravity estimate: ABV = (OG − FG) × 131.25. Enter specific gravity before and after fermentation, not a sugar percentage or an uncorrected Brix reading. The current fields accept OG from 1.000 to 1.200 and FG from 0.990 to 1.050, with OG greater than FG; those input bounds are not an accuracy guarantee.
Can I enter a refractometer reading?
Use hydrometer readings corrected to the instrument's calibration temperature. Alcohol changes refractometer readings after fermentation: raw refractometer values need an appropriate alcohol correction and instrument calibration before conversion to specific gravity. This calculator performs neither correction.
Why are the standard drinks labeled U.S.?
The result uses the U.S. definition: 14 g of ethanol per standard drink. In the example, 71.01 ÷ 14 = 5.07, displayed as 5.1 U.S. equivalents. Definitions differ by country; this count is an amount comparison, not a personal safe-drinking limit or a blood-alcohol estimate.
Are these total beverage calories?
Example: 750 ml at 12% ABV contains 90 ml ethanol. Using the approximate density 0.789 g/ml gives 71.01 g, displayed as 71 g. Ethanol energy is 71.01 × 7 = 497.07 kcal, displayed as 497. This excludes energy from sugar and other ingredients.