Calculadora de Teor Alcoólico (ABV)
- Created by
- Renato Passos, Eng. de Software
- Reviewed by
- Renato Passos, Eng. de Software
Last updated: Apr 18, 2026
Formula
ABV = (OG - FG) × 131,25
About this calculator
This Alcohol by Volume (ABV) calculator is designed for homebrewers and winemakers who need to estimate the alcohol percentage of their beverages. Using original gravity (OG) and final gravity (FG), the calculation follows the formula ABV = (OG - FG) × 131.25. The result is a reliable approximation, widely used in homebrew recipes.
To use the tool, measure the wort density before fermentation (OG) and after fermentation (FG) with a hydrometer or refractometer. Enter the values in the corresponding fields and click calculate. The calculator returns the ABV as a percentage. This method is standard for beers and wines, but minor variations may occur due to other compounds present.
Use this calculator whenever you want to track fermentation progress or adjust recipes. For example, when testing new yeast strains or ingredients, ABV helps predict body and residual sweetness. It is also useful for comparing batches and ensuring consistency in production.
Important precautions: ensure density readings are corrected for the hydrometer's calibration temperature (usually 20°C). Highly attenuative yeasts can yield lower FG, increasing ABV. Remember that the formula is an estimate; for absolute accuracy, laboratory methods are required.
Frequently asked questions
What do OG and FG mean?
OG (Original Gravity) is the density of the wort before fermentation. FG (Final Gravity) is the density after fermentation. The difference indicates how much sugar was converted to alcohol.
Do I need to correct density for temperature?
Yes, most hydrometers are calibrated at 20°C. If your sample is at a different temperature, use a correction table or a hydrometer with automatic temperature compensation.
Does the formula work for wines and beers?
Yes, the formula ABV = (OG - FG) × 131.25 is widely used for both. For high-alcohol wines, some sources suggest multiplying by 131.25 or 132, but the difference is small.
What if my FG is higher than OG?
This usually indicates a measurement error. Check that values were entered correctly and that your hydrometer is clean and calibrated. FG should never be higher than OG.
Can I use this calculator for distilled spirits?
No, distilled spirits require different methods such as chromatography or alcohol-specific hydrometers. This calculator is only for fermented beverages like beer and wine.