ABV Calculator
Calculate the Alcohol By Volume of your homebrew using your Original Gravity and Final Gravity readings.
Estimate alcohol by volume from OG and FG
Use the ABV calculator to estimate beer strength from original gravity and final gravity readings in specific gravity or Plato.
ABV formula example
A beer with 1.050 OG and 1.010 FG has a gravity drop of 0.040. The common estimate is (OG - FG) x 131.25, which gives about 5.25% ABV.
- Measure original gravity before fermentation starts.
- Measure final gravity after fermentation has stabilized.
- Enter both readings in the same unit system to estimate ABV.
Watch for: If either gravity reading was warm, correct it first with the hydrometer correction calculator.
Frequently asked questions
What readings do I need for ABV?
You need original gravity before fermentation and final gravity after fermentation is complete.
Should I correct hydrometer readings first?
Yes. If the sample was not near the hydrometer calibration temperature, correct OG and FG before calculating ABV.
Why is ABV an estimate?
Homebrew ABV formulas approximate alcohol from gravity change, so lab measurements can differ slightly.
Can I use Plato readings?
Yes. Select Plato when your measurements are in Plato instead of specific gravity.
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