Alcohol leaves the blood slowly and at a roughly steady rate. Georgian law puts that rate at about 0.15 per mille per hour. So the more you drink, the more hours have to pass, and there’s nothing you can do to speed it up.
We didn’t make this number up. It’s written in the note to Article 116 of the Code of Administrative Offences (in Georgian), the article on drink driving.
How fast does alcohol leave your body?
On average, by about 0.15 per mille an hour. But that’s an average: for some people it’s faster, for others slower, and even for the same person it differs from day to day.
Alcohol is processed mainly by the liver, and the liver works at its own pace. Many things play a part: weight, sex, whether you ate, how tired you are, whether you’ve taken medication. So any calculation is only approximate.
How many hours do you need to wait?
A simple example: if you had 1.2 per mille in your blood at the end of the night, at 0.15 an hour it takes about 8 hours to get to zero, and about 6 hours to get down to 0.3, the legal limit.
| In your blood at the end of the night | Down to 0.3 per mille | Down to zero |
|---|---|---|
| 0.6 per mille | ~2 hours | ~4 hours |
| 0.9 per mille | ~4 hours | ~6 hours |
| 1.2 per mille | ~6 hours | ~8 hours |
| 1.5 per mille | ~8 hours | ~10 hours |
The table is only a rough guide. For simplicity it uses the average rate from the code. Your body may actually work more slowly. And most importantly, you don’t really know how many per mille you had at the end of the night.
Why is the morning after risky too?
Because sleep doesn’t speed alcohol up. If you were drinking until 3 am and got up at 8, your body had only 5 hours to clear the alcohol.
Plenty of people get caught exactly in the morning: they feel fine, but the device shows more than 0.3. And the law doesn’t care whether it’s evening or morning: it’s the same 6 months or 1 year without a licence.
Coffee, a cold shower, fresh air: do they work?
No. Coffee may perk you up, but it won’t take the alcohol out of your blood. The US National Institute on Alcohol Abuse and Alcoholism (NIAAA) says the same: cold showers, hot coffee and walking do not reverse the effects of alcohol, even in the case of an overdose.
The same goes for chewing gum, mints or “soaking it up with food”. They change the smell, not the reading.
Can you check with a breathalyser or an app?
Apps that “calculate” your per mille from your weight and the number of drinks only use an average formula. They don’t know how much you ate, how fast you drank or how your body works. A number like that isn’t worth risking your licence on.
A home breathalyser is better, but cheap models are often inaccurate and need calibrating. And, as you’ll see below, the alcohol level can even rise for a while after the last drink. So the tester may show “0.25” and half an hour later a different number.
The only reading that matters is the one on the police device. And if you doubt it, the code gives you 2 hours to request a laboratory test.
Can the level rise after you stop drinking?
Yes, sometimes. According to NIAAA, blood alcohol can continue to rise even when a person stops drinking, because alcohol still in the stomach and intestines keeps entering the bloodstream.
So half an hour after your last drink you may be more “drunk” than you were while drinking it. That often coincides with exactly the moment you’re walking to the car.
So when is it safe to drive?
The safest answer: don’t drive at all on the day you drank, and be careful the next morning too if you drank a lot. If you’re in doubt, it’s too early.
Practical options:
- decide in advance who will drive back, and that person doesn’t drink at all;
- leave the car at home if you know you’ll be drinking;
- call a sober driver if you’ve already come by car. They’ll take you home in your own car, and you won’t have to fetch it in the morning.
Our number is +995 597 333 200, any time of the night.