© 2025 Babal Tools
Calculate Alcohol by Volume from OG and FG.
Switch between Standard (for most beers) and Alternate (for high ABV) calculation methods.
Automatically calculates Apparent Attenuation to help you monitor yeast performance.
Get a rough estimate of calories per 12oz serving based on alcohol and residual sugars.
Input precise gravity readings up to 3 decimal places (e.g., 1.050).
The ABV Calculator is a fundamental tool for any brewer. It determines the percentage of alcohol in your beverage by comparing the density of the liquid before fermentation (Original Gravity) and after fermentation (Final Gravity). This tool provides both the standard formula for typical beers and an alternate formula for high-gravity beverages like wine or imperial stouts. It also estimates the Apparent Attenuation and calorie content per 12oz serving.
Take a hydrometer reading of your wort before adding yeast (Original Gravity).
Allow fermentation to complete.
Take a hydrometer reading of the finished beer (Final Gravity).
Enter both numbers to see your ABV, Attenuation, and estimated calories.
Enter your specific gravity measurements
ALCOHOL BY VOLUME
Apparent Attenuation
--%
Calories (Est. 12oz)
~--
For most beers (below 6% ABV), the standard formula is very accurate. However, as alcohol content rises, the relationship between fluid density and refraction changes, making the Alternate formula more precise for High Gravity beers, wines, and meads.