Blood alcohol concentration

Blood alcohol concentration (BAC) is the amount of alcohol in the bloodstream. A BAC of 0.05 means the person has 0.05 grams of alcohol in every 100ml of their blood.

Factors affecting your BAC

The more a person drinks, the higher their BAC. However, two people who drink thesame amount might register quite different BACs. This is due to a range of factors, including:
  • Body size: A smaller person will have a higher BAC than a glasslarger person, because the alcohol is concentrated in a smaller body mass.
  • Empty stomach: Someone with an empty stomach will reach a higher BAC sooner than someone who has just eaten a meal. Food in the stomach slows down the rate at which alcohol passes into the bloodstream.
  • Body fat: People with a lot of body fat tend to have higher BAC. Alcohol is not absorbed into fatty tissue, so the alcohol is concentrated in a smaller body mass.
  • Gender: After consuming the same amount of alcohol, a female will almost always have a higher BAC than a male.
    Because of all these variable factors, counting the number of standard drinks you consume can only give a rough guide to your BAC.
Have a go at the Drink meter below to test how well you can estimate your BAC.

Download Drink Meter

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