ABV Calculator

Calculate alcohol by volume from original and final gravity

What are you calculating?

Reading unit

Original Gravity (OG)

Final Gravity (FG)

Final reading taken with a refractometer (correct for alcohol)

Sample temperature (°F, optional)

Hydrometer calibration (°F)

Formula

Standard Advanced (high-gravity)

Frequently Asked Questions

How is ABV calculated from gravity readings? ▼

The standard homebrewing formula is ABV = (OG − FG) x 131.25, where OG is the original gravity measured before fermentation and FG the final gravity after it finishes. OG 1.050 and FG 1.010 give 0.040 x 131.25 = 5.25% ABV.

What's the difference between the standard and advanced formula? ▼

The standard formula is accurate to about 0.3% for most beers up to an OG of about 1.070. For stronger beers, wines and meads the advanced formula, 76.08 x (OG − FG) ÷ (1.775 − OG) x (FG ÷ 0.794), is more accurate because it accounts for alcohol's lower density. At OG 1.090 and FG 1.015 the standard formula gives 9.84% and the advanced 10.65%.

Can I calculate ABV from Brix readings? ▼

Yes. Choose Brix as the unit. The original Brix converts directly to gravity, but a refractometer reads falsely high once alcohol is present, so tick the refractometer option and the calculator corrects the final reading with the Terrill formula and a 1.04 wort correction factor.

What if I don't know my original gravity? ▼

You need an OG reading taken before fermentation; there is no reliable way to get ABV afterward from the final gravity alone. If you have a refractometer and a hydrometer, a final reading from each can estimate OG, but the result is rough.

Does temperature affect my gravity reading? ▼

Yes. Hydrometers are calibrated at a set temperature, usually 60°F (some at 68°F). A sample at 80°F reads about 0.002 low, which understates OG. Enter the sample and calibration temperatures and the calculator corrects the readings.

How do I calculate the ABV of a mixed drink? ▼

Multiply each ingredient's volume by its ABV, add those up and divide by the total volume, including any water from ice. 1.5 oz of 40% vodka in 4.5 oz of orange juice is 0.6 ÷ 6 = 10% ABV. Use the mixed drink mode above.

ABV calculator: quick answer

To calculate ABV, subtract the final gravity from the original gravity and multiply by 131.25: ABV = (OG − FG) x 131.25. A beer that starts at 1.050 and finishes at 1.010 is 0.040 x 131.25 = 5.25% ABV. For strong beers, wine and mead (OG above about 1.070) the advanced formula is more accurate. The calculator above also accepts Brix or Plato, corrects refractometer and temperature readings, and has a mode for mixed drinks.

How to calculate ABV from gravity readings

Homebrewers measure specific gravity with a hydrometer or refractometer before fermentation (original gravity, OG) and after it ends (final gravity, FG). Yeast turns sugar into alcohol and CO₂, so the gravity drops. The calculator offers two formulas:

Standard: ABV = (OG − FG) × 131.25
Advanced: ABV = (76.08 × (OG − FG) ÷ (1.775 − OG)) × (FG ÷ 0.794), which is more accurate for strong beers, wines and meads

Examples

A pale ale from OG 1.050 to FG 1.010: (0.040) × 131.25 = 5.25% ABV; the advanced formula gives 5.34%.
A strong ale from OG 1.090 to FG 1.015: the standard formula gives 9.84% while the advanced formula gives 10.65%, showing why the simple version underestimates high-gravity brews.

ABV chart: OG minus FG

Gravity drop (OG − FG)	Standard ABV	Example
0.030	3.94%	1.038 to 1.008, light lager
0.035	4.59%	1.045 to 1.010, session ale
0.040	5.25%	1.050 to 1.010, pale ale
0.045	5.91%	1.056 to 1.011, American IPA
0.050	6.56%	1.062 to 1.012, strong IPA
0.060	7.88%	1.060 to 1.000, dry cider
0.070	9.19%	1.085 to 1.015, double IPA
0.100	13.13%	1.095 to 0.995, dry red wine

Mixed drink ABV

For cocktails, ABV = total pure alcohol ÷ total volume. Each ingredient contributes volume x ABV. A margarita of 2 oz tequila (40%), 1 oz triple sec (40%) and 1 oz lime juice holds 1.2 oz of alcohol in 4 oz, which is 30% before ice. Shaking with ice adds roughly 25% water, bringing it to about 24% ABV, or two US standard drinks.

Typical gravity ranges

Drink	Typical OG	Typical FG	ABV
Light lager	1.035 to 1.042	1.004 to 1.008	about 4%
Pale ale, IPA	1.045 to 1.065	1.008 to 1.014	5% to 7%
Imperial stout	1.075 to 1.115	1.018 to 1.030	8% to 12%
Dry wine	1.085 to 1.100	0.990 to 0.998	12% to 14%

Tips for accurate readings

Correct for temperature. Hydrometers are calibrated at a set temperature, usually 60°F or 68°F; warm samples read low.
Confirm fermentation is finished. The FG should stay the same over two or three days.
Refractometers need correction once alcohol is present, so use a refractometer correction formula for the final reading.
Degas the sample so bubbles do not lift the hydrometer.

Potential alcohol from original gravity

If a beer, wine or mead fermented all the way down to 1.000, the original gravity alone sets the maximum possible ABV. Use this chart to plan a recipe or to check whether a reading makes sense:

Original gravity	Potential ABV (to 1.000)	Typical drink
1.040	5.3%	session beer
1.050	6.6%	pale ale
1.060	7.9%	IPA, cider from sweet apples
1.070	9.2%	strong ale
1.080	10.5%	barleywine, light wine
1.090	11.8%	table wine
1.100	13.1%	full-bodied wine, mead
1.120	15.8%	sack mead, dessert wine (before sweetening)

Beer rarely ferments to 1.000 because malt contains sugars yeast cannot use, so expect real beer ABV to be lower than the potential figure. Wine, cider and mead usually ferment dry, below 1.000, and can slightly exceed it.

Using a refractometer or Brix

Winemakers often measure sugar in degrees Brix. As a rule of thumb, 1 °Brix is about 0.004 specific gravity, so 24 °Brix grape juice is roughly 1.100 SG. Before fermentation a refractometer reading converts cleanly; after alcohol appears it reads falsely high, so use a hydrometer for the final gravity or apply a refractometer correction formula.

ABV, ABW and proof

ABV (alcohol by volume) is the standard on US labels.
ABW (alcohol by weight) is about 0.8 × ABV, because ethanol is lighter than water. A 5% ABV beer is about 4% ABW.
Proof in the US is exactly twice the ABV, so 40% ABV spirits are 80 proof.

Homebrewing beer and wine for personal use is legal under federal law within household limits, though some local rules differ. To see how many standard drinks a serving of your brew contains, use the standard drink calculator, to estimate blood alcohol the BAC calculator, and to convert volumes and temperatures the unit converter.