Alcohol By Volume (ABV) Calculator
Calculate the alcohol by volume (ABV) of your homebrew beer, wine, or cider from original gravity (OG) and final gravity (FG). Also get apparent attenuation, estimated calories per serving, and the number of US standard drinks.
mL
Accurate formula: 5.34 %
- 1
Gravity drop (OG − FG)
1.05 − 1.01 = 0.04 - 2
ABV (simplified formula)
0.04 × 131.25 = 5.3Standard homebrewer formula: (OG − FG) × 131.25.
How does this calculator work?
ABV ≈ (OG − FG) × 131.25 for most beers and wines. Example: OG 1.050, FG 1.010 → ABV ≈ 5.25 %. A more accurate formula (Miller) is available for high-gravity brews. The calculator also estimates apparent attenuation, calories per serving, and US standard drinks from the alcohol content.
Formula
How this is calculated
When yeast ferments wort or juice, it converts sugars into alcohol and CO₂, lowering the specific gravity of the liquid. Original gravity (OG) measures the sugar content before fermentation; final gravity (FG) measures residual sugar after fermentation is complete. The difference (OG − FG) is directly proportional to how much alcohol was produced.
The simplified formula ABV ≈ (OG − FG) × 131.25 is derived from the weight-to-volume relationship of ethanol and gives results accurate to within about 0.1–0.2 % ABV for most ales and lagers. For stronger beers or meads (OG > 1.080) the Miller/more-accurate formula — ABV = (76.08 × (OG − FG) / (1.775 − OG)) × (FG / 0.794) — is preferred because it accounts for the non-linearity between gravity and sugar concentration at higher starting gravities.
Apparent attenuation = (OG − FG) / (OG − 1) × 100 % tells you what fraction of the original extract was fermented. Calories come from both alcohol (7 kcal/g) and residual carbohydrates (roughly (FG − 1) × 1 000 × volume × 4 kcal/g). One US standard drink contains 14 g of pure alcohol.
Frequently asked questions
The simplified formula (OG − FG) × 131.25 is an approximation derived under typical wort conditions. The more accurate Miller formula corrects for the varying relationship between gravity and sugar concentration at high OG. For light beers (OG < 1.070) the difference is usually under 0.2 %; it grows for high-gravity beers. The accurate formula is the better choice for strong ales, wines, and meads.
Most ales finish between 1.008 and 1.015 depending on malt bill and yeast strain. Highly attenuating yeasts can push FG below 1.005. If your hydrometer reads the same FG over two consecutive days, fermentation is complete. Wines and ciders typically finish lower, around 0.990–1.005.
A 355 mL (12 fl oz) serving at 5 % ABV contains roughly 150–160 calories. Alcohol contributes most of the calories (ethanol = 7 kcal/g), with residual sugars (FG) adding the rest. Light beers at 3.5–4 % ABV with a lower FG typically fall around 100–110 calories per can.
TG we-Calculate Editorial Team. (2026). Alcohol By Volume (ABV) Calculator [Online calculator]. TG we-Calculate. https://we-calculate.com/calculator/alcohol-by-volume-calculator
TG we-Calculate Editorial Team. "Alcohol By Volume (ABV) Calculator." TG we-Calculate. 2026. https://we-calculate.com/calculator/alcohol-by-volume-calculator.
TG we-Calculate Editorial Team, "Alcohol By Volume (ABV) Calculator," TG we-Calculate, 2026. [Online]. Available: https://we-calculate.com/calculator/alcohol-by-volume-calculator
@misc{wecalculate_alcohol_by_volume_calculator, title = {Alcohol By Volume (ABV) Calculator}, author = {{TG we-Calculate Editorial Team}}, howpublished = {\url{https://we-calculate.com/calculator/alcohol-by-volume-calculator}}, year = {2026}, note = {TG we-Calculate} }
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