Alcohol

Calculate alcohol content (ABV/ABW), attenuation, and calories from gravity readings.

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.

Enter OG and FG to get important stats about your product

How to Use

1. Enter Original Gravity (OG)

   • Measure your wort gravity before fermentation begins

   • Input the value in your preferred unit (SG, Plato, or Brix)

2. Enter Final Gravity (FG)

   • Measure gravity when fermentation is complete

   • Use the same unit system as your OG for consistency

3. 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

Related docs

• Batches

• Fermenting