Factsheets Alcohol in the Blood

As soon as you start drinking your BAC begins to rise. Having one standard drink will raise an average person's blood alcohol level by about .015%. It takes around 30-60 minutes after you stop drinking for your BAC to reach its highest concentration, before it starts falling. If you have a late night out drinking, you may still be over the limit the next morning. 

Your blood alcohol level depends on:

Your weight. To get a high blood alcohol level, a smaller person needs fewer drinks than a large person. This is mainly because they have less fluid to water it down inside their body.

Your gender. On average, the same number of drinks gives a woman a higher blood alcohol level than a man of the same weight.

Eating. Alcohol takes longer to go into the blood if there is food in your stomach.

How long you spend drinking. If you have a number of drinks over a short time it will give you a higher alcohol level than if you take longer to drink them.

Getting your BAC back down takes time. There are no quick fixes. No amount of coffee, water, mints, bread or physical activity will make it go down faster. Your BAC will fall as your liver processes the alcohol. Generally, the liver processes about 1 standard drink per hour, but this will vary depending on the size and health of the person.

Keeping your BAC within legal limits

If your legal limit is 0.00% BAC, then you cannot drink any alcohol at all. If your limit is 0.05%, then the following guidelines may keep your BAC within the legal range.

  • Men - No more than 2 standard drinks in the first hour, and 1 standard drink each hour after that.
  • Women - No more than 1 standard drink each hour.

However, there are many ways this can go wrong, and having any alcohol at all will affect your driving. If you are going to drive, we recommend you don't drink at all.