ABV Calculator

What is Alcohol By Volume?

Alcohol by volume is a measure of how much ethanol a drink contains, expressed as a percentage of total liquid volume. It's the standard used on virtually every bottle and can sold in the world and forms the basis of health guidelines, legal limits for driving, and tax calculations in most countries.

The number tells you something concrete: a 440ml can of 5% beer contains 22ml of pure ethanol. A 750ml bottle of 13% wine contains 97.5ml. Understanding ABV lets you compare drinks across categories, keep track of how much alcohol you're actually consuming, and — for brewers — verify that fermentation has done its job.

Calculating ABV from Gravity Readings

Brewers and winemakers measure specific gravity — the density of liquid relative to water — at two points: before fermentation begins (original gravity, OG) and after fermentation is complete (final gravity, FG). The drop in density tells you how much sugar yeast converted into alcohol.

The simple formula

Works well for beers, ciders, and anything under about 10% ABV:

The advanced formula

More accurate for wines, strong ales, and anything with an OG above 1.070:

Reading your hydrometer

Most hydrometers are calibrated at 20°C (68°F). If your sample is warmer or cooler, the reading will be slightly off. A rough correction: add 0.001 to your gravity reading for every 3°C above 20°C, subtract for cooler. For the OG reading, the sample should be chilled to roughly room temperature before measuring — hot wort gives misleadingly low readings.

What attenuation tells you

Attenuation is the percentage of sugars the yeast consumed. Most ale yeasts attenuate 70–80%; lager yeasts and highly-fermentable worts can reach 85%+. A much lower attenuation than expected usually means fermentation stalled — possibly from temperature, underpitching, or yeast health issues.

Standard Drinks by Country

The standard drink is a unit of measurement that strips away the container — it expresses alcohol in terms of pure ethanol content, so you can meaningfully compare a pint of stout with a glass of wine. The amount defined as "one standard drink" differs by country, which is why guidelines like "no more than 14 units per week" (UK) and "no more than 14 standard drinks per week" (US) sound the same but refer to different amounts of alcohol.

Typical ABV Ranges by Drink Type

ABV varies enormously across drink categories. The ranges below cover the vast majority of commercially produced drinks — outliers exist in every category, especially in the craft brewing world where everything from 1% table beer to 28% freeze-concentrated barleywines can be found.

Common questions

• What does ABV actually mean?
  ABV stands for Alcohol By Volume — the percentage of a drink's total volume that is pure ethanol. A beer labelled 5% ABV contains 5ml of ethanol for every 100ml of liquid. It's the universal standard used on labels, in brewing, and for legal limits worldwide, though a few countries still use "proof" (which in the US is simply double the ABV).
• Why do homebrewers use original and final gravity to measure ABV?
  Yeast converts sugar into alcohol and CO₂. Gravity measures the density of the liquid relative to water — sugary wort is denser than water, so it has a gravity above 1.000. As fermentation progresses, sugars are consumed, density drops, and you're left with a lighter, alcoholic liquid. The difference between where you started (original gravity, OG) and where you finished (final gravity, FG) directly reflects how much sugar was converted, which tells you how much alcohol was produced. You can't measure ABV directly mid-ferment without a distillation test, so this indirect method is what almost every homebrewer uses.
• What is the difference between the simple and advanced ABV formulas?
  The simple formula — ABV = (OG − FG) × 131.25 — is accurate to within ±0.2% for most beers and ciders in the normal ABV range (3–9%). It's fast and good enough for homebrew purposes. The advanced formula accounts for the fact that ethanol is lighter than water and that the relationship between gravity drop and alcohol isn't perfectly linear at higher gravities. For wines, strong ales, and anything over roughly 10% ABV, the advanced formula gives a meaningfully more accurate result.
• What counts as one standard drink?
  A standard drink contains a fixed amount of pure alcohol regardless of what the drink is — but the definition varies by country. In the United States it's 14 grams (about 17.7ml) of pure ethanol, equivalent to a 355ml (12 oz) beer at 5%, a 148ml (5 oz) glass of wine at 12%, or a 44ml (1.5 oz) shot of 40% spirits. In the UK it's 8 grams, in Australia 10 grams. The standard drink concept exists so that health guidelines can be expressed in a way that's meaningful across different types of alcohol.
• How accurate are gravity-based ABV readings?
  For most homebrewed ales, lagers, and ciders in the 3–10% range, the simple gravity formula is accurate to within ±0.3%. Accuracy depends on the quality of your hydrometer or refractometer, the temperature at which you take readings (most instruments are calibrated at 20°C/68°F — correct for temperature if you measure at a different temperature), and whether fermentation is actually complete. Refractometers need an additional correction factor when alcohol is present in the wort because alcohol bends light differently to sugar solution.
• Can I calculate ABV without a hydrometer?
  Without gravity readings, your options are limited. You can look up the stated ABV on commercial products, use a wine or beer recipe's expected attenuation to estimate, or use a distillation-based ebulliometer (rarely practical for home use). Some brewers use a refractometer for OG and then apply a correction algorithm for FG, but a hydrometer is the most reliable and affordable tool for the job — they cost around £5–10 and give direct, reliable readings.