ABV Calculator
Free Abvcalculator Calculator for drinks recipes. Enter amounts to convert, scale, or adjust ingredients precisely. Enter your values for instant results.
Reviewed by Daniel Agrici, Founder & Lead Developer
Formula
ABV = (OG - FG) x 131.25
Where OG = Original Gravity (before fermentation), FG = Final Gravity (after fermentation). The constant 131.25 converts the gravity difference into alcohol percentage by volume. Apparent Attenuation = (OG - FG) / (OG - 1.000) x 100.
Worked Examples
Example 1: Standard Pale Ale ABV
Problem:A pale ale has an original gravity of 1.055 and final gravity of 1.012. Calculate the ABV and apparent attenuation.
Solution:ABV = (OG - FG) x 131.25\nABV = (1.055 - 1.012) x 131.25\nABV = 0.043 x 131.25 = 5.64%\n\nApparent Attenuation = (OG - FG) / (OG - 1.000) x 100\n= (1.055 - 1.012) / (1.055 - 1.000) x 100\n= 0.043 / 0.055 x 100 = 78.2%
Result:ABV: 5.64% | Apparent Attenuation: 78.2%
Example 2: Imperial Stout Calorie Count
Problem:An imperial stout has OG 1.090, FG 1.022, served in a 16oz pint. How many standard drinks is this?
Solution:ABV = (1.090 - 1.022) x 131.25 = 8.93%\nAlcohol in oz = (8.93 / 100) x 16 = 1.429 oz pure alcohol\nStandard drinks = 1.429 / 0.6 = 2.38 standard drinks\n\nThis imperial stout contains roughly 2.4 standard drinks per 16oz pint, which is significantly more than a typical light beer (about 0.8 standard drinks per 12oz).
Result:ABV: 8.93% | Standard Drinks per Pint: 2.38
Frequently Asked Questions
What is ABV and how is it calculated?
ABV stands for Alcohol By Volume, representing the percentage of a beverage that is pure alcohol. It is calculated using the original gravity (OG) and final gravity (FG) readings taken with a hydrometer or refractometer before and after fermentation. The standard formula is ABV = (OG - FG) x 131.25. For example, a beer with an OG of 1.050 and FG of 1.010 has an ABV of (1.050 - 1.010) x 131.25 = 5.25%. The principle works because yeast converts sugar into alcohol and carbon dioxide during fermentation. Since alcohol is lighter than water, the gravity reading decreases as sugar is consumed, and the difference between the two readings directly correlates with alcohol content.
References
Reviewed by Daniel Agrici, Founder & Lead Developer · Editorial policy