ABV Calculator
Use our free ABV calculator to instantly work out the alcohol by volume of your homebrew beer, wine, or cider. Simply enter your original gravity (OG) reading before fermentation and your final gravity (FG) reading once fermentation is complete.
Calculate ABV from Gravity Readings
Enter your original and final gravity to calculate alcohol by volume and attenuation
How Is ABV Calculated?
The standard formula used by homebrewers is:
ABV = (OG − FG) × 131.25
For example, if your original gravity was 1.050 and your final gravity is 1.010:
ABV = (1.050 − 1.010) × 131.25 = 5.25%
This formula is accurate for most homebrew beers up to around 8% ABV. For higher-gravity brews, a more precise formula may be needed.
Typical ABV Ranges for Homebrew Styles
Not sure what gravity readings to expect? Here are common OG/FG ranges and typical ABV for popular homebrew styles:
| Style | Typical OG | Typical FG | Typical ABV |
|---|---|---|---|
| Session Ale | 1.035–1.040 | 1.006–1.010 | 3.3–4.5% |
| Pale Ale / IPA | 1.050–1.065 | 1.008–1.014 | 4.7–7.5% |
| Stout / Porter | 1.045–1.065 | 1.010–1.018 | 4.0–7.0% |
| Country Wine | 1.080–1.110 | 0.990–1.000 | 10.5–15.0% |
| Cider | 1.045–1.065 | 1.000–1.010 | 4.6–8.5% |
| Lager | 1.044–1.055 | 1.006–1.012 | 4.2–5.7% |
Frequently Asked Questions
What is OG and FG?
OG (original gravity) is the density of your wort or must before fermentation begins. FG (final gravity) is the density once fermentation is complete. The difference between the two tells you how much sugar has been converted to alcohol.
How do I measure gravity?
You can measure gravity using a hydrometer or a refractometer. A hydrometer is the most common tool for homebrewers and gives a direct specific gravity reading.
My FG seems too high — has fermentation stalled?
If your FG is higher than expected, fermentation may have stalled. Check your temperature, give the fermenter a gentle swirl, and ensure your yeast was healthy and pitched at the right rate.
Can I use this calculator for wine and cider?
Yes — the formula works for any fermented beverage. Just enter your OG and FG readings as measured by your hydrometer.
Need more brewing tools? Try our Hydrometer Calculator for temperature correction and Brix conversion, or browse our full range of hydrometers and homebrew equipment.