-Male or female
-How long the time frame was while drinking
-How long it takes to get back to a 0 BAC
A BAC of .04 means you have 4 drops of pure alcohol for every 10,000 drops of blood. An average man at 160 lbs. that drinks two beers would have a BAC of .04 after about an hour, on an empty stomach. Someone who reaches a BAC of .10 will normally show signs of intoxication. On average, it takes about 1 hour for 1 drink to leave the body. On women, it takes long because usually women have lower water in their body and have a higher percent of body fat than men. The fatter you are, the longer the alcohol stays in your system.
First, the alcohol is absorbed through your stomach. When you eat, then the alcohol is absorbed into the food and has to go on to the intestinal track for absorption. This takes longer for the alcohol to be absorbed. It all depends on how much you drink and how much you eat. A small amount may be absorbed through the stomach, but most alcohol is absorbed through the intestines where it enters the blood stream and travels to the brain.
Alcohol is a system suppressor along with other drugs like sedatives, painkillers and marijuana. Other drugs have a different effect on impaired driving, like cocaine and amphetamines, which are system enhancers. Alcohol impairs judgment, coordination, vision, and reaction time and increases drowsiness.
This is how your BAC is calculated and consequently gets you thrown into jail for a DWI. 35% of those convicted of DWI will become repeat offenders. Its simple, don't drink and drive.
Stuart Simpson Information on DWI's at