Anything more than a drink and driving is too much. You might legally be able to get away with a little bit more, but why risk it? In the past 41 years, I've represented hundreds, probably thousands of people charged with DUI or more serious DUI-related offences, like hitting somebody, injuring somebody, killing somebody, and I've watched lives ruined. Don't drink and drive. Call a friend, call Uber, take a taxi, do whatever you've got to do, but don't think you can just make it home, it's okay. It's not okay, don't drink and drive. And if you do, and if you're arrested, don't take the test, don't admit to drinking, say as little as possible, call a criminal defense attorney who understands representing people charged with DUI. Period.