Alcohol
The Alcohol calculator helps you determine the alcohol content, attenuation, and nutritional information of your beer based on Original Gravity (OG) and Final Gravity (FG) measurements.

How to Use
Enter Original Gravity (OG)
Measure your wort gravity before fermentation begins
Input the value in your preferred unit (SG, Plato, or Brix)
Enter Final Gravity (FG)
Measure gravity when fermentation is complete
Use the same unit system as your OG for consistency
View Results
All calculations update automatically
Results are shown in your preferred units from Settings
What This Tool Calculates
Alcohol Content
ABV (Alcohol by Volume) - The percentage of alcohol by volume in your finished beer
ABW (Alcohol by Weight) - The percentage of alcohol by weight, used in some regions
Attenuation
Apparent Attenuation - The percentage of sugars that appear to have been consumed by yeast
Real Attenuation - The actual percentage of sugars consumed, accounting for alcohol's effect on gravity
Extract Values
Original Extract - The Plato equivalent of your original gravity
Apparent Extract - The Plato equivalent of your final gravity
Real Extract - The actual remaining extract, correcting for alcohol presence
Nutritional Information
Calories - Estimated calories per serving (per 100ml or per 12 oz)
Carbohydrates - Estimated carbs per serving
Kilojoules (kJ) - Energy content in kilojoules
Understanding the Results
ABV Ranges by Style
Light Beers: 2.5-4.5% ABV
Standard Beers: 4.5-6% ABV
Strong Beers: 6-9% ABV
Very Strong Beers: 9-14% ABV
Attenuation Guidelines
Low Attenuation: 65-70% (sweeter, fuller body)
Medium Attenuation: 70-75% (balanced)
High Attenuation: 75-80% (drier, lighter body)
Very High Attenuation: 80-85%+ (very dry)
Tips for Accurate Measurements
Temperature Correction: Always correct hydrometer readings for temperature
CO2 Degassing: Degas samples before taking FG readings to avoid CO2 affecting the measurement
Multiple Readings: Take readings over several days to confirm fermentation is complete
Calibrate Equipment: Regularly check hydrometer calibration with distilled water
Using with Your Brewing
The tool remembers your last entered OG and FG values
Use alongside your batch tracking for consistent results
Reference the calculated values when logging your batch data
Troubleshooting
High Final Gravity
Check yeast health and fermentation temperature
Consider yeast nutrient additions
Lower than Expected ABV
Verify OG measurement accuracy
Ensure fermentation completed fully
Unexpected Attenuation
Different yeast strains have varying attenuation levels
Mash temperature affects fermentability
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