What is a Standard Drink?
At Armstrong Legal, we receive a lot of enquiries from people who have been caught drink driving. They often say to us “but I only had four drinks in four hours, how could I be over the limit? I felt fine to drive.” It is sometimes said that to remain under the limit, an average-sized man should have no more than two standard drinks in the first hour of drinking and no more than one drink per hour after that, while an average-sized woman should have no more than one standard drink per hour. But what is a standard drink?
Standard drinks in Australia
In Australia, a standard drink contains 10g of alcohol. What quantifies as a standard drink differs significantly depending on the type of alcohol. The following are standard drinks sizes for various types of alcohol:
The question of what is a standard drink isn’t complicated if you are drinking a bottle or can of beer or cider or a pre-mixed drink as all alcohol containers sold in Australia have the number of standard drinks marked on the container.
Standard drinks of beer and cider
Many bottles of full-strength beer and cider contain more than one standard drink. For example, a 375mL bottle of full-strength beer is usually 1.4 standard drinks. If an average-sized male drinks three of those in two hours, they would have consumed 4.2 standard drinks in 2 hours. This could put them over .05.
If you are drinking tap beer or cider, a 285mL glass (pot or middy) of full-strength beer is approximately one standard drink. A 425mL glass (schooner) of mid-strength beer is approximately 1.2 standard drinks. A 425mL (schooner) glass of light beer is approximately one standard drink.
A pint of mid-strength beer is approximately 1.5 standard drinks, and a pint of full-strength beer is approximately 2.1 standard drinks. If an average-sized male drinks three pints of full-strength beer in two hours, they would have consumed 6.3 standard drinks in two hours. This is likely to put them well over 0.05% and possibly even over 0.08% or 0.15%.
Spirits and standard drinks
Many premixed spirit cans and bottles also contain more than one standard drink per can or bottle, with some containing as much as 1.8 standard drinks per can.
A standard drink of spirits is 30mL. If someone else is making your drinks, they could be made with more than the standard 30mL, even in a bar if there is a generous bartender. If your friend is making the drinks, they could be free pouring the spirits and each drink may contain a lot more than 30mL of spirits.
When it comes to wine or sparkling wine, a standard drink is 100mL. A 750mL bottle of wine usually contains approximately seven to 7.5 standard drinks. Red wine usually has a higher percentage of alcohol than white wine or sparkling.
Wine glasses also range significantly in size and volume. Some wine glasses can hold as much as 500mL. An average-sized wine glass holds approximately 250mL.
If you are drinking wine in a restaurant, the waiter will usually pour you a glass of wine which greatly exceeds a standard drink of 100mL. In addition, your glass may be topped up before you finish it. This makes it very difficult to count your drinks. If you are going to drink wine, it’s best to leave the car at home.
The rule of thumb for how much a person can drink per hour is based on an average-sized man and woman. Many other factors can affect a person’s blood-alcohol level such as:
- Body fat levels
- Whether they have eaten
- How often they drink alcohol
- How their body processes alcohol
- The medication they are on
If you are someone who regularly has a few drinks and then drives home, buying a good quality personal Breathalyzer could moderate your risk.
Drink driving is a serious offence and can have significant consequences for your life and that of your family. Almost all drink driving offences carry mandatory minimum disqualifications, substantial fines and, in serious and repeated cases, imprisonment. More importantly, you may have a motor vehicle accident and seriously harm or kill someone.
If you require legal advice or representation in any legal matter, please contact Armstrong Legal.