Alcohol Content (ABV) Calculator
Calculate the alcohol by volume (ABV) of homemade beer, wine, or other fermented beverages using original and final gravity readings.
🍺 Brewing📐 ABV = (Original Gravity - Final Gravity) x 131.25
Original gravity (OG)
Final gravity (FG)
Please enter valid values.
Formula & Reference
| Variable | Formula | Units |
|---|---|---|
| Alcohol Content (ABV) Calculator | ABV = (Original Gravity - Final Gravity) x 131.25 | % |
Step-by-Step Examples
Example 1
Standard Homebrew Beer
OG 1.055, FG 1.012.
- ABV = (1.055-1.012) x 131.25 = 5.64%
- Good for an IPA or pale ale
✓ 5.64% ABV
Example 2
Dry Red Wine
OG 1.095, FG 1.000.
- ABV = (1.095-1.000) x 131.25 = 12.47%
✓ 12.47% ABV
Example 3
Strong Stout
OG 1.080, FG 1.020.
- ABV = 0.060 x 131.25 = 7.88%
✓ 7.88% ABV
Real-World Applications
Homebrewers
Calculate actual alcohol content from gravity readings.
Winemakers
Verify ABV of homemade wine.
Fermenters
Understand fermentation completion from gravity.
Recipe Developers
Design beverages to target specific ABV ranges.
Common Mistakes to Avoid
⚠️
Not waiting for fermentation to finish
If FG is still dropping, ABV will increase. Take readings 2-3 days apart; if stable, fermentation is complete.
⚠️
Temperature affecting hydrometer readings
Standard hydrometers are calibrated at 60F. Correct for temperature if measuring at a different temperature.
Frequently Asked Questions
How to measure OG and FG? ▾
Use a hydrometer (float in a sample) or refractometer. Hydrometer is more accurate for FG (sugar from unfermented wort affects refractometer readings).
What is attenuation? ▾
Attenuation = how much of the available sugar the yeast consumed. 70-80% is typical for most beer yeast. Lower = sweeter, fuller body; higher = drier, lighter.
What gravity indicates fermentation complete? ▾
Most beers: FG between 1.008-1.020. Compare to recipe's expected FG. Two identical readings 48 hours apart = fermentation complete.