How Long Alcohol Stays In Your System

We’ve all heard people claim that they “Sober up” very quickly, just as we’ve seen people who appear to stay drunk well into the night despite having only a few drinks.

Actually, both of these statements are provably false. Alcohol is one of the most predictable chemical reactions for your body. It burns off at an almost perfectly precise rate of .016 BAC per hour, about equal to 1 standard drink each hour (depending on your weight). This rate is true regardless of the size of your body. A 5’2 female burns off alcohol at the same rate as a 6’1 obese male.

The differences, however, are in the rate with which your BAC rises. One drink in a small female of low weight constitutes a much larger percent of her BAC. It may take a male 5 drinks or more in an hour to reach a BAC of .08, while it may take a small female only 2 or 3.

Also, it tends to take longer for individuals with a lot of fat to absorb the alcohol. In other words, if two people of different fat levels but of equal weight drink the exact same amount of alcohol, the one with less fat will absorb the alcohol faster, causing them to feel the effects of alcohol quicker. The individual with more fat will absorb it slower, and all the while the alcohol they are absorbing is still metabolising at the same rate, so they will not experience as much of a sensation.

Regardless of size or gender, though, the .016 metabolic rate is a constant. So if you are trying to remove all the alcohol from your system, refer to the chart featured on this page to understand alcohol metabolism rates and how long different BAC levels take to wear off.

BAC Level Hours Until Zero
.016 1
.05 3.75
.08 (UK/US legal driving limit) 5
.10 6.25
.16 (2x legal) 10
.20 12.5
.24 (3x legal) 15

You will also notice on this table that if you are at a BAC of .24 (which is very drunk - you will likely be stumbling and risk blacking out) you will still have alcohol in your body the next day, and you will still be legally drunk for 10 more hours. Despite what many people believe, there is no way to speed up this process. Coffee may make you more alert, but it will not get rid of the alcohol that is still in your body.

Estimate Your BAC Level

To help estimate your BAC (blood alcohol content) level, we have created a very simple BAC calculator tool based on a basic version of the Widmark Formula. To use this tool you will need to provide a few pieces of information such as your gender, weight, number of standard drinks and finally how long since you started drinking. Once you have entered this information, the tool will estimate your BAC level and give you a rough idea of how long the resulting BAC level would take to pass through your system. Please note, this tool provides an estimate and you should not drive a vehicle if you have any alcohol in your system.

Try The BAC Calculator Tool