ABV Calculator
Built by Johnny Alto · free, no sign-up · updated July 26, 2026
Enter your original gravity and final gravity to find the alcohol by volume of your beer, wine, mead, or cider. You also get apparent attenuation, and an alternate formula that stays accurate for stronger brews where the simple version drifts high.
Alcohol by volume0%standard formula
ABV (alternate)0%better above ~6.5%
Apparent attenuation0%sugar fermented
Take both readings at the same temperature, or correct them, since gravity shifts with heat. The standard formula is accurate to roughly 6 to 7 percent; use the alternate figure for strong beers, wines, and meads.
How to calculate ABV from gravity
Alcohol by volume comes from how much sugar the yeast turned into alcohol, which you measure as the drop in gravity. The simple, widely used formula is the original gravity minus the final gravity, multiplied by 131.25. For a beer that started at 1.050 and finished at 1.010, that is 0.040 times 131.25, or about 5.25 percent.
The simple formula gets a little optimistic on strong brews. The alternate formula shown corrects for that and stays accurate well into wine and mead territory, so use it once you are past roughly six and a half percent. Both need honest gravity readings: take them at the same temperature or correct for it, because a warm sample reads low.
What apparent attenuation tells you
Apparent attenuation is the share of available sugar the yeast fermented, figured as the gravity drop divided by the original gravity above water. A typical ale lands around 75 percent. A low number can mean a stuck or unfinished fermentation, while a very high number points to a dry, well-attenuated brew. Reading it alongside ABV gives you a fuller picture of how fermentation went.
Recommended gear
Measure and ferment it right
Frequently asked questions
How do you calculate ABV?
Subtract the final gravity from the original gravity and multiply by 131.25. A brew from 1.050 to 1.010 is about 5.25 percent alcohol by volume.
Why are there two ABV formulas?
The simple times-131.25 formula is easy and accurate to about 6 to 7 percent. The alternate formula corrects for the way alcohol affects density and stays accurate for strong beers, wines, and meads.
What is apparent attenuation?
It is the percentage of sugar the yeast fermented, calculated from the gravity drop. Most ales finish around 75 percent; a low figure can signal a stuck fermentation.
Do I need to correct gravity for temperature?
Yes. Hydrometers are calibrated to a set temperature, usually 60 or 68 degrees Fahrenheit, and a warm sample reads low, so correct the reading or take it at the calibrated temperature.
More calculators
This calculator gives estimates for planning only; always confirm against your own measurements and species research. Some links are to our buying guides, which contain affiliate links. As an Amazon Associate I earn from qualifying purchases.
← All calculators · Buying guides · About · Affiliate Disclosure · Privacy Policy