how long would i have to wait before driving
A common guideline is that after each typical drink, you must wait 45 minutes before attempting to drive. If you have another drink, you must add another 45 minutes. You've had a drink and must wait 45 minutes before driving. A quarter hour later, you have another drink. Now you must wait 45 minutes PLUS the 30 minutes left over from the first drink. That's one and a quarter hours before you should drive.