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.
How to use it
- Take an OG reading with your hydrometer before pitching yeast.
- Take an FG reading once fermentation is complete (gravity stable for 2 days running).
- Enter both readings below — your ABV appears instantly.
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 — the jar holds the sample so the hydrometer can float freely. 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
- Priming Sugar Calculator — how much sugar to add when bottling beer or cider
- Keg Line Balancing Calculator — perfect draught beer at home
- Strike Temperature Calculator — hit your mash temperature first time
- Hydrometer Temperature Adjustment — correct readings taken at non-standard temperatures
Don't have the kit yet? Buy a Young's Hydrometer and a Trial Jar at BrewCo UK — essential kit for any home brewer. For full instructions on how to use one, see our ABV and hydrometer guide.