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ABV Calculator

Calculate alcohol by volume (ABV) for homebrewing using original and final gravity readings.

Gravity Readings

ABV Results

Standard Formula

131.25 × (OG - FG)
5.25%

Alternate Formula

(1.05 / 0.79) × (OG - FG) × 100
5.32%

Complex Formula

(76.08 × (OG - FG) / (1.775 - OG)) × (FG / 0.794)
5.34%

About ABV Calculation

ABV (Alcohol By Volume) is calculated using the difference between your original gravity (OG) reading taken before fermentation and your final gravity (FG) reading taken after fermentation is complete. Different formulas exist, each with varying accuracy depending on the specific beer style and fermentation conditions.

How to Use

  1. Take a hydrometer reading of your wort before pitching yeast - this is your Original Gravity (OG)
  2. After fermentation is complete, take another reading - this is your Final Gravity (FG)
  3. Enter both values into the calculator to see ABV results from different formulas

About the Formulas

  • Standard Formula - A simplified calculation suitable for most beers
  • Alternate Formula - Uses density adjustments for improved accuracy
  • Complex Formula - An empirical formula that accounts for non-linear relationships in higher gravity beers