How much have you drunk, when did you stop drinking, and when do you plan to drive?
Crucial questions to answer if you want remain safe and legal to drive - and avoid a drink drive conviction.

How long does it take?
This website explains how to calculate roughly how long it takes to be alcohol free.

On top of the times given here, you need to add an hour - this is how long it takes for alcohol to be absorbed into your blood stream.

It takes about one hour for your body to rid itself of each unit of alcohol, but can take much longer. It depends on factors including how healthy you are and how much you've eaten.

Eating a big meal means alcohol is absorbed more slowly - so it takes longer to sober up.