A unit of alcohol (as displayed increasingly on beer bottles and cans) is defined as a measure of 10 ml of pure alcohol. To calculate the number of units in a beer, use the following formula.

Volume in millilitres (ml) x % alcohol by volume (ABV)

1000

Example, for a 500 ml bottle of beer of 5%:	500 ml x 5%	= 2.5 units
	1000

For bottles and cans measured in fluid ounces (as in the USA), use the following formula.

Volume in fluid ounces (fl oz) x % alcohol by volume (ABV)

33.8

Example, for a 12 fluid ounce bottle of beer of 5%:	12 fl oz x 5%	= 1.78 units
	33.8