It takes approximately one hour for a single unit of alcohol to eradicate itself from your system. There are 3.2 units in one 660ml bottle of Budweiser.
Therefore, four bottles of Budweiser contain 12.8 units of alcohol, and would take roughly 13 hours to leave your system. This can vary between individuals, however, and here's why.
Men can often absorb alcohol differently to women. This is generally due to the differences in body composition between men and women. However, alcohol absorption can also be affected by a woman's menstrual cycle.
Weight
The weight of a person can have a massive effect on alcohol absorption, with smaller people have less room within their body for alcohol to be distributed.
Medication
Medication can effect the rate alcohol is absorbed and eliminated, and some medications require that you do not take alcohol when using them.
As you can see, there are varying factors in how quickly alcohol is eliminated from the body. It is suggested that each unit of alcohol takes one hour to leave the body, but this is not always a reliable guide.
