What is a unit of Alcohol?

A unit of alcohol is a simple way of estimating the amount of pure alcohol in a drink and stands at around 10ml or 8g of pure alcohol.

According to the South African breweries, as a general rule for responsible drinking, one should aim to consume nothing more than one unit of alcohol per hour which amounts to about 10ml of pure alcohol.

One should however aim to have 0 units of alcohol in their system while driving as even a unit of alcohol in the human body can impair driving ability and though processes.

The amount of units in a drink depends upon its size and strength.

A simple way to calculate the amount of units in a drink is to multiply the size of the bottle and the strength of the alcohol and then divide by 1000 which will give you the number of units. For examples, wine at 12% in a 750 ml bottle would have 9 units in it.

Rough estimates of the amount of units found in popular alcoholic beverages are as follows:

  • Standard glass of wine: 2.1 units
  • “Draft glass” of low strength beer: 2 units
  • “Draft glass” of high strength beer: 3 units
  • Bottle of lager: 1.7 units
  • Cider: 1.5 units
  • Single spirit with mix: 1 unit

On average, it takes an adult an hour to process one unit of alcohol. However if you weigh below 68 kg, it is important to realize that your body will take a longer amount of time to process alcohol. Women generally are affected more quickly and on smaller amounts of alcohol than men and so they need to drink slower and less than men.