how long beer stays in system
Adding up your units. If you drink a large (250ml) glass of wine, your body takes about three hours to break down the alcohol. If you drink one pint of beer, your body takes about two hours to break it down. One pint of strong lager is equivalent to three units, so this will take longer. However, this time can vary depending on the factors mentioned above. If you have a few drinks during a night out, it can take many hours for the alcohol to leave your body. The alcohol could still be in your blood the next day.