Beer ABV calculator
Brewing at home? Enter your original gravity (OG) and final gravity (FG) to get the strength of your beer.
The formula
ABV ≈ (OG − FG) × 131.25
(1.050 − 1.010) × 131.25 = 5.25% ABV.
That simple formula is accurate for most beers up to about 7–8%. For big beers (barley wines, imperial stouts) the "advanced" formula above is closer, because the relationship between sugar and alcohol stops being linear.
Tips for a reliable reading
- Take readings at the temperature your hydrometer is calibrated for (often 20 °C / 68 °F), or correct for it.
- Wait until FG is stable for two or three days before bottling.
- Refractometers read differently once there's alcohol in the beer; use a correction calculator for FG.
ontap is the free iPhone app for logging beers in one tap and seeing which friends are out.
Get ontap free on the App StoreFAQ
What's a normal original gravity?
Most everyday ales and lagers start around 1.040–1.055. Stronger IPAs and stouts often start at 1.060–1.080 or more.
What does attenuation mean?
How much of the sugar the yeast ate. 70–80% apparent attenuation is typical for ales.