Alcoholic units
In the UK a system of alcoholic units is employed for an approximate measure of the amount of alcohol in different drinks.
Quantities
As a rough guide:
- A normal glass of wine or sherry, a single measure of spirits and a half pint of beer each contain about one unit, or 8 g (0.25 oz) of alcohol.
- A large glass of red or white wine or half a pint of cider contains about 12g (3/8oz), or one and a half units. However strong lager may contain as much as two units per half pint.
Formula
The number of units of alcohol in a drink can be determined by multiplying the volume of the drink in millilitres by its percentage ABV, and dividing by 1000. Thus a pint of beer at 4% ABV contains
<math>\frac{(568 \times 4)}{1000} = 2.3\mbox{ units}<math>
Limits
It is recommended by the government that men drink no more than 21 units and women 14 units a week. The difference between genders is given due to the (typically) lower weight and water-to-body-mass-ratio of women.
See also: standard drink
