Brewing tool

ABV Calculator

Use your original and final gravity readings to get a quick ABV estimate.

Guide

Before you start

Take the original gravity before fermentation and the final gravity once fermentation is done. The drop between the two gives you the ABV estimate.

Calculator

Enter your values

Before fermentation starts.
After fermentation has finished.
Clear

Method

How this is estimated

ABV is estimated from the drop between original gravity and final gravity. This quick formula is a good brew day check for most beers.

ABV ≈ (OG - FG) × 131.25

Safety and limits

A few notes

This is only as good as the readings you put in. If you used a refractometer after fermentation, correct that reading first.

Use accurate measurements for the best estimate.