Alcohol by volume (abbreviated as abv, ABV, or alc/vol) is a standard measure of how much alcohol (ethanol) is contained in an alcoholic beverage (expressed as a percentage of total volume). The ABV standard is used worldwide.
Another way of specifying the amount of alcohol is alcohol proof, which in the United States is twice the alcohol-by-volume number.
Alcohol content of various drinks
Low-alcohol beer (also called non-alcoholic or NA beer, small beer, small ale, or near-beer) is beer with very low or no alcohol content. Most low-alcohol beers are lagers, but there are some low-alcohol ales.
In the United States, beverages containing less than 0.5% alcohol by volume (ABV) were legally called non-alcoholic, according to the now-defunct Eighteenth Amendment. Because of its very low alcohol content, non-alcoholic beer may be legally sold to minors in most American states.
If you ever wanted to calculate the abv, I've included how that's actually done.During the production of wine and beer, yeast is added to a sugary solution. During fermentation, the yeast organisms consume the sugars and produce alcohol. The density of sugar in water is greater than the density of alcohol in water. A hydrometer is used to measure the change in specific gravity (SG) of the solution before and after fermentation. The volume of alcohol in the solution can then be calculated.
The simplest method for wine has been described by C.J.J. Berry:
The calculation for beer is:
Where 1.05 is number of grams of ethanol produced for every gram of CO2 produced and .79 is the density of ethanol alcohol,
However, many brewers use the following formula: