How many units of alcohol can you drink when driving?

In the UK the drink driving limit is:

35 micrograms of alcohol in 100 millilitres of breath; or

80 milligrams of alcohol per 100 millilitres of blood; or

107 milligrams of alcohol per 100 millilitres of urine.

The legal drink drive limit cannot be safely converted into a certain number of units, as it depends on a number of factors to include gender, body mass and how quickly your body absorbs alcohol into the blood stream.