ABV calculator

Alcohol by volume from original and final gravity — the classic brewer's formula plus a precise alternative.

Original gravity − final gravity → alcohol by volume, plus apparent attenuation.

Standard formula (OG−FG)×131.25 drifts high at big gravities; the alternate tracks lab values closer. Gravity 0.990–1.200; FG must be below OG.

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How to use

  1. Enter the original gravity (e.g. 1.050).
  2. Enter the final gravity (e.g. 1.010).
  3. Read ABV both ways, ABW, and apparent attenuation.

What it supports

OG and FG each 0.990–1.200 with OG > FG. Standard ABV = (OG−FG)×131.25 and the alternate (76.08·(OG−FG)/(1.775−OG))×(FG/0.794) are both shown.

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