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ABV & Attenuation Calculator
Calculate alcohol content and fermentation efficiency from gravity readings
Temperature Correction (Optional)
Calculated Results
Alcohol by Volume
6.30%
Apparent Attenuation
79.6%
Est. Calories (12 oz)
424
ABW
5.00%
Real Attenuation
65.2%
OG (SG)
1.0603
FG (SG)
1.0123
About This Calculator
This calculator uses the standard formula: ABV = (OG - FG) × 131.25
Apparent attenuation shows the percentage of sugars converted during fermentation. Real attenuation accounts for the presence of alcohol in the final gravity reading.
Temperature correction is applied using the standard hydrometer correction formula for readings taken at temperatures other than the calibration temperature (usually 60°F/15.6°C).
Understanding the Results:
- ABV (Alcohol by Volume) - The percentage of alcohol in your beer by volume
- ABW (Alcohol by Weight) - The percentage of alcohol in your beer by weight
- Apparent Attenuation - The percentage of available sugars that appear to have been consumed
- Real Attenuation - The actual percentage of sugars consumed, accounting for alcohol's effect on density
- Calories - Estimated calories per 12 oz serving based on alcohol and residual extract
Frequently asked questions
- How do you calculate ABV from gravity?
- ABV is estimated from original gravity (OG) and final gravity (FG): ABV (%) ≈ (OG − FG) × 131.25. For higher-gravity beers a more accurate formula is ABV = (76.08 × (OG − FG) / (1.775 − OG)) × (FG / 0.794).
- What is a typical ABV for beer?
- Most beers fall between about 4% and 7% ABV. Session beers run 3–4%, standard ales and lagers 5–6%, and strong styles like imperial stouts or triple IPAs can exceed 8–12%.