ABV Calculator — Calculate Alcohol Content of Home Brew Beer and Wine

Use this free ABV calculator to instantly find the alcohol content of your home brew beer, wine, or cider. All you need is two hydrometer readings — your Original Gravity (OG) before fermentation and your Final Gravity (FG) once fermentation is complete.

Enter your original gravity (OG) and final gravity (FG) to find out your batch's alcohol by volume (ABV)

Original Gravity (From Hydrometer)
Finishing Gravity (From Hydrometer)
ABV %

How do you calculate ABV of home brew?

The standard formula is: ABV% = (OG − FG) × 131.25. For example, if your OG was 1.050 and your FG is 1.010, your ABV is (1.050 − 1.010) × 131.25 = 5.25% ABV. The calculator above uses a slightly more precise alternate formula that accounts for the density of alcohol — both methods give very similar results for typical home brew strengths.

What do you need to measure ABV?

You need a hydrometer and a tall trial jar to take readings in. Take your OG reading before pitching yeast, and your FG reading once fermentation is complete (when the gravity has been stable for 2 consecutive days). Without these two readings, ABV cannot be accurately calculated.

What should the FG of home brew beer be?

Most standard kit beers finish between 1.006 and 1.012 FG. If your FG is higher than expected (above 1.014–1.016 for a kit beer), fermentation may not be complete — check the temperature and give it more time before bottling. Never bottle based on time alone; always confirm with a hydrometer.

Quick ABV reference table

OG FG ABV% Typical style
1.038 1.008 3.9% Mild, session bitter
1.044 1.010 4.5% Standard ale
1.050 1.010 5.25% IPA, premium lager
1.058 1.012 6.0% Strong ale, stout
1.070 1.014 7.35% Imperial stout, barleywine

More free home brew calculators

Don't have a hydrometer yet? Buy a Young's Hydrometer at BrewCo UK — essential kit for any home brewer. For full instructions on how to use one, see our ABV and hydrometer guide.