How long alcohol stay in your system?

Depends: This depends on how much you drink and the period of time over which you drink it; also, it correlates with sex (males metabolize better than females); how much you've eaten; food delays the absorption of alcohol; it depends on your tolerance: if you drink regularly in a moderate fashion, you will metabolize alcohol more efficiently;.

Alcohol in body: It depends on genetic predisposition. Some people has enormous amount of enzymes to digest alcohol rapidly and not get drunk with +++ beers while other cannot tolerate more than 2B due to lack of that enzyme, leading to very slow elimination of alcohol from the body. Women have half of men's enzyme to digest alcohol.