How is ABV calculated from gravity?

The standard homebrew formula multiplies the gravity drop (OG minus FG) by 131.25 to estimate ABV percent.

ABV Calculator — Alcohol by Volume

Calculate alcohol by volume from original and final gravity for homebrewing. Free ABV calculator.

Original gravity (OG)

Final gravity (FG)

Formula used

ABV % = (OG − FG) × 131.25

Examples

Try a sample calculation

1.050 → 1.010

Typical ale

Standard brewing formula.

Works with hydrometer readings.

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Run the calculation and read the breakdown, not just the headline number.
Adjust inputs to compare scenarios, or open a related Rankify calculator for the next step.

Solve percent increase, decrease, and part-of-whole problems.