ABV (Alcohol By Volume) Calculator

If you are a home-brewer who loves creating homemade beer or wine, the ABV, or alcohol by volume calculator will enable you to make a reliable estimation of the alcohol your brew contains. Using original and final gravity readings, you can also determine how many units of alcohol there are in your drink according to your national guidelines.

Using the Calculator

First, choose the formula to calculate your brew's ABV. Then, depending on the measuring device you are using, choose Degree Plato or Specific Gravity. Next, enter your readings, both for original gravity (OG) and final gravity (FG). If you also wish to determine the number of alcohol units in a drink, select a country and type in the drink's volume. Finally, click "Calculate".

Understanding Alcohol by Volume

Often expressed as ABV or alc/vol, alcohol by volume is a standard measurement of the alcohol or ethanol content in an alcoholic drink.

Part of the process of producing beer or wine involves adding yeast to a sugary solution. As the liquid ferments, the sugars are consumed by the yeast and it is this process that produces alcohol. Alcohol density in water is less than sugar density in water, and thus variations in a solution's specific gravity (SG) pre and post-fermentation are measured using a hydrometer (a device that measures the SG or density of a liquid in relation to water). This enables the alcohol volume of a solution to be estimated.

A few different formulas can be used to determine ABV (scroll down to the bottom of the page to see a list).

Units of Alcohol Calculation

A straightforward approach to illustrating the alcohol content of a drink is to use units of alcohol. These units are typically represented by ABV, or alcohol by volume.

The ABV of a drink is represented as a percentage of the full volume of the drink and measures how much pure alcohol it contains.

To illustrate, if the total volume of a bottle of wine consists of 12% pure alcohol, it will be described as "alcohol volume 12%" or "12% ABV".

A standard glass of wine is 175ml. Assuming the wine is 12% ABV, to calculate how many units of alcohol are in a standard glass of wine, the following equation applies:

12 (%) x 175 (ml) / 1,000 = 2.1 units.

Formulas

The ABV Calculator uses the following formulas:

Alcohol by Volume Formula (Standard)

ABV = (OG - FG) * 131.25

Alcohol by Volume Formula (Alternate)

ABV = 76.08 * (OG - FG) / (1.775 - OG) * (FG / 0.794)

Alcohol By Weight (ABW) Formula

ABW = ABV * 0.79336

Specific Gravity to Degrees Plato Formula

Plato = (135.997 * SG³) - (630.272 * SG²) + (1111.14 * SG) - 616.868

Degrees Plato to Specific Gravity Formula

SG = 1 + (Plato / (258.6 - ( (Plato / 258.2) * 227.1) ) )

Other Formulas

Proof (UK) = ABV / 0.5706

Proof (US) = ABV / 0.5

No. of Units of Alcohol = ABV (%) * Volume of Alcohol (ml) / 1000