How long does it take for alcohol to leave your system
â¢ It would take approx 6.66 hours for .15 BAC of alcohol to leave your body. â¢ And for 1.5 BAC of alcohol it would take approximately 10 hours for your body to completely excrete alcohol. There are some steps that may help you to control the BAC count of alcohol in your system.his is equal to 4 ounces of wine, 12 ounces of beer, 10 ounces of microbrew. This means, if you have three standard drinks, irrespective of how long it took for you to drink them, it can take three hours for the alcohol to leave your system through urine.