How long does alcohol stay in your system?

The human body breaks down alcohol at the average rate of about 0.6 fluid ounces of pure alcohol per hour, says the National Health Service. This rate varies due to a variety of factors including age, weight and sex.

Different kinds of alcoholic beverages have varied concentrations of pure alcohol. For example, 12 fluid ounces of 5 percent beer contains as much alcohol as 5 fluid ounces of 12 percent wine and 1.5 ounces of 80-proof liquor. These drinks are all equivalent to 0.6 fluid ounces of pure alcohol, according to the National Institutes of Health. Ethyl glucuronide, a chemical resulting from the body metabolizing alcohol, is detectable in urine up to 80 hours after alcohol consumption, according to Addict Help.