Alcohol By Volume
Alcohol By Volume (ABV) is a measure of the percentage of alcohol volume over the total volume of the beer. This is equivalent to the proof value of higher alcohol liquors. Beer typically has an alcohol by volume value of between 3 and 8%. Barley wine may have an ABV as high as 10% or more. Note that while the majority of the world typically quotes alcohol by volume, in the US alcohol percentage is often measured as Alcohol By Weight.
- ABV = (Orig_gravity - Final_gravity) * 131
or to be a little more precise try:
- ABV = ((1.05 * (Starting SG – Final SG)) / Final SG) / 0.79 * 100