How long does Alcohol stay in my blood?

You need to be aware of how long alcohol stays in your bloodstream, and at what sort of rate it dissipates. If you don’t, you could find yourself for drunk driving, many hours after you last drank

The rate at which alcohol dissipates from your blood

On average your body breaks down one unit of alcohol per hour. However, you must bear in mind that this is an average figure only. The actual rate per person varies on a number of factors, including:

  • A person’s body weight
  • A person’s gender
  • The subject’s age
  • An individual person’s metabolic rate
  • How much food the subject has consumed
  • The type and strength of the alcohol consumed
  • Whether or not the subject is taking any medication
  • The state of a person’s liver health

Quick guide to drinks and alcohol unit measures

Knowing approximately how long your body takes to process one unit of alcohol is one thing, but you also need to know how much alcohol you have consumed. Here is a quick guide to the number of units in “standard” drinks.

  • 1 x 175ml standard glass of average strength (12%) wine – 2.1 units
  • 1 x 250ml large glass of average strength (12%) wine – 3 units
  • 1 pint of low strength (3.6%) beer, cider, or lager – 2 units
  • 1 pint of high strength (5.6%) beer, cider, or lager – 3 units
  • I single measure of spirits – 1 unit
  • 3 units in a pint of higher-strength lager, beer or cider (5.2%)

The above table is based on one unit being 10ml or 8g of pure alcohol.

Calculating how long it takes to clear your body system of alcohol

If you’re going out for an evening’s drinking, you must total all of the alcoholic drinks you have consumed to arrive at the total number of units you have consumed. At the average dissipation rate of 1 unit per hour, you can then see long it will take your body system to clear itself.

This information comes to you courtesy of the well-man and well woman clinics at Broadgate GP Clinic London Wall.