The Australian Standard Drink
A standard drink is any drink containing 10 grams of alcohol. One standard drink always contains the same amount of alcohol regardless of container size or alcohol type, that is beer, wine, or spirit. A standard drink is a unit of measurement. In the same way one metre measures a particular distance travelled, one standard drink measures a particular amount of alcohol consumed.
What is the standard drink used for?
Instead of counting glasses or containers, drinkers count standard drinks as a way of
keeping track of how much alcohol they consume. Counting standard drinks is a much more reliable measure of how much alcohol is consumed compared to counting glasses, bottles, or cans. Counting glasses, bottles, or cans of alcohol can be misleading because they can contain varying amounts of alcohol.
The consumption limits in the Australian Alcohol Guidelines are based on the
standard drink concept.
How many standard drinks in....?
The number of standard drinks in alcohol beverages is always shown on the label of
the container. Examples of how many standard drinks are in typical containers can be found here.
Bar and restaurant staff can help in identifying how many standard drinks are in
glasses, jugs, and other containers that are not labelled. Restaurants and bars do not all have the same size glasses, so the number of standard drinks can vary from one licensed venue to the next.
How are standard drinks calculated?
The formula for calculating standard drinks is:
Volume of Container in Litres multiplied by the percentage of alcohol volume multiplied by 0.789, equals the number of standard drinks. (0.789 is the specific gravity of ethyl alcohol.)
For example, one stubbie of 375ml of full strength beer 5% alcohol by volume:
0.375 multiplied by 5 multiplied by 0.789 equals 1.5 standard drinks
0.375 X 5 X 0.789 = 1.5 standard drinks
How to count Standard Drinks?
Counting standard drinks is simply a matter of adding numbers. For example if a person has one nip of spirits and two average restaurant glasses of wine, they would have consumed 4 standard drinks, that is 1 + 1.5 + 1.5
An average serve of wine is usually 150ml. Depending on the venue, glass size can vary from 120 to 180ml.
Some people put a bottle cap or a coaster in their pockets to represent every drink
they have. This is not as accurate as counting standard drinks but it is better than not counting.
When counting standard drinks, people should be aware of bar staff or others topping up glasses or where the amount of alcohol is not known such as in mixed drinks, cocktails or punch.
The main reason people count their drinks, using standard drinks, is to ensure that
the low risk levels set out in the Australian Alcohol Guidelines are not
exceeded. The low risk levels define the number of standard drinks that can be drunk before the threat to a person's health and social well-being moves up into the risky or high risk category.