Drinking and Driving is a terribly irresponsible thing to do. Most states have a legal limit of 0.08 or 0.10 Blood Alcohol Level. This is the maximum level your BAC can be before you face penalties (Like losing your license and ooodles of cash, not to mention getting jail time.) There is a formula that you can use to determine your BAC. This formula requires four factors

The TYPE OF ALCOHOLIC BEVERAGE you have consumed.

YOUR WEIGHT in POUNDS

THE NUMBER OF DRINKS YOU HAVE CONSUMED

THE TIME PERIOD IN HOURS THAT YOU HAVE SPENT DRINKING

This formula is not perfect, nor should it be used to gauge a life or death decision to drive but you can experiment with a few variables to determine acceptable levels to stay within while you are drinking.