It is impossible to state categorically how many units you can consume before exceeding the BAC legal limit, as the speed that alcohol enters your blood stream will vary radically if you are having a drink on an empty stomach, or drinking with food over a prolonged period.

Tiredness will also affect your concentration and absorption.

The only safe advice is to nominate a non drinking driver for the evening or to arrange to get home by taxi or public transport. See toptips for more information.

Drink-drive legislation varies across the world so always be careful if you are travelling. Most countries in the EU have a drink drive Blood Alcohol Concentration of 50mg per 100 ml blood, 30mg less than the UK's limit of 80mg. The UK has some of the toughest penalties on drink driving in the world. If you're caught over the limit, you face an automatic driving ban of twelve months and a possible fine of up to £5,000 and/or 6 months in prison.

For information on BAC levels and the law relating to countries worldwide please click here