Beer ABV Calculator

Enter your original and final specific gravity to estimate alcohol by volume, apparent attenuation and a rough calorie count for a 12 oz serving.

How to calculate ABV

Typical pale ale

OG 1.050, FG 1.010

ABV 5.25%, attenuation 80%

Stronger beer

OG 1.060, FG 1.015

ABV 5.91%, attenuation 75%

How is ABV calculated from gravity?

This tool uses the common homebrew estimate ABV = (OG - FG) x 131.25, where OG and FG are specific gravity readings.

What is apparent attenuation?

Apparent attenuation is the share of sugar the yeast consumed: (OG - FG) / (OG - 1) x 100. Most ales finish near 70 to 80 percent.

Are the calories exact?

No. The calorie figure is a rough rule of thumb based on ABV and a 12 oz serving. Real values depend on residual sugars and the recipe.

What gravity values are valid?

Readings must sit between 0.9 and 1.2, and final gravity cannot exceed original gravity. Out of range numbers are rejected.

Should I correct gravity for temperature?

Yes. Hydrometers are calibrated to a set temperature, so adjust your reading first for the most accurate ABV estimate.