Alcohol

Don’t risk trying to calculate your BAC

Trying to calculate your BAC is impossible. Your BAC begins to rise as soon as you start drinking and can continue to increase for up to two hours after you have stopped drinking. Counting standard drinks to guess your BAC is difficult and often inaccurate because:

• Alcohol concentrations vary between drinks, such as light beer (2.5%), full strength beer (5%), wine (14%) and spirits (40% or higher)
• Beer may be served in schooners, middies and schmiddies. Wine glasses vary in size from 100ml to 280ml or more
• Drinks are often ‘topped up’ so it's impossible to know how many standard drinks you’ve had
• Drinks come in non-standard sizes – many pre-mixed drinks sold in bottles or cans may contain more than one standard drink and 800ml bottles may contain three standard drinks 
  

People are different

Alcohol also affects people differently. Two people who drink the same amount can have different BACs. This is caused by factors such as:

• A deep understanding of how alcohol affects the body can greatly enhance personal safety. 
• Size and weight – a smaller person will have a higher BAC from the same amount of alcohol
• Gender – a woman the same height and weight as a man, drinking the same amount, will have a higher BAC
• Liver function – an unhealthy liver will process alcohol slower than a healthy liver
• Recent consumption of food – lack of food in your stomach means you will absorb alcohol into your blood faster. However, eating food after you have been drinking will not reduce your BAC
• Fitness, fatigue and general health condition – your BAC can be higher if you are not feeling well, you are tired, stressed or unfit

Key facts about Alcohol from WHO

• The harmful use of alcohol is a causal factor in more than 200 disease and injury conditions.
• Worldwide, 3 million deaths every year result from harmful use of alcohol. This represents 5.3% of all deaths.
• Overall, 5.1% of the global burden of disease and injury is attributable to alcohol, as measured in disability-adjusted life years (DALYs).
• Beyond health consequences, the harmful use of alcohol brings significant social and economic losses to individuals and society at large.
• Alcohol consumption causes death and disability relatively early in life. In people aged 20–39 years, approximately 13.5% of total deaths are attributable to alcohol.
• There is a causal relationship between harmful use of alcohol and a range of mental and behavioural disorders, other noncommunicable conditions and injuries.

Visit WHO site