How long does alcohol stay in your system?
Blood alcohol level and sobering-up time
About you
Men and women hold a different share of body water, which changes the result.
Use height and age (Watson)
Works out your own distribution factor instead of the average for your sex.
What you drank
Tap to add a drink
No drinks added yet.
Another drink
Pure alcohol: 0 g= 0 standard drinks
Time since the first drink
Enter your body weight to see a result.
Estimate only, not a basis for deciding whether to drive. The only safe choice is not to drive after drinking. Disclaimer
Enter what you drank and the calculator shows the hours until your reading should be back to 0.00 ‰ — and the time until it drops under the legal limit where you drive.
How to use the How long alcohol stays in your system
- Enter your weight and the drinks you had.
- Set the time since the first drink.
- Read the hours left to zero at the top, and the curve below it.
Method: BAC = A / (r × W) − β × t · r 0.68 / 0.55 · β 0.15 ‰/h · 0.08 % · Updated October 26, 2026
How fast does alcohol leave the body?
Once alcohol is in your blood, your liver clears it at a nearly steady rate, not in proportion to how much is there. For an average adult that is about 0.15 ‰ an hour, with real values running roughly between 0.10 and 0.20. In US units that is about 0.015 % an hour.
A steady rate has an awkward consequence: the time you need is set by the peak, not by how you feel. From 1.2 ‰ it takes about eight hours to reach zero on an average liver and twelve on a slow one, whatever you do in between. That is why the morning after is a real risk, and why so many drink-driving cases are people who slept and believed that was enough.
Nothing speeds it up
- Coffee, energy drinks and cold showers change how awake you feel, not how much alcohol is in your blood.
- Water helps a hangover. It does not lower your reading.
- Eating before and while you drink slows absorption, so your peak is lower — but it does not shorten the time from a given peak.
- Exercise, sauna and fresh air clear a negligible fraction. Your liver does essentially all of it.
- Sleep does not count for extra. Eight hours of sleep clears the same as eight hours awake.
How long alcohol shows up in a test
Driving is about blood and breath, and both follow the curve above. Other tests look much further back, which is why the answers people find online disagree so widely: a urine screen can pick up alcohol metabolites for a day or more, and an EtG test for several days, long after your blood is at zero. None of that is relevant to whether you can drive — for that, only the current reading counts.
The morning after
Finish drinking at two in the morning on 1.5 ‰ and you are near 0.9 ‰ at six and still over Germany's 0.5 ‰ limit at eight. Set the calculator to the time you stopped and look at the curve before you plan a morning drive. If there is any doubt at all, do not drive — see the legal limit of your country.
Related guides
Frequently asked questions
How long does one beer stay in your system?
A 0.33 l beer at 5 % puts roughly 0.2 to 0.3 ‰ into an average adult, so it clears in about one and a half to two hours on an average liver, up to three on a slow one. A 0.5 l beer takes two to three hours, up to four and a half.
How long after drinking can I drive?
Long enough for your reading to be 0.00, and the only honest way to know that is not to be unsure. Use the hours this page gives as a lower bound, add a margin, and if the answer is anywhere near your departure time, do not drive.
Can I still be over the limit the next morning?
Easily. A heavy night can leave you over a 0.5 ‰ limit at eight or nine in the morning, and over a 0.2 ‰ limit well into the afternoon.
Does body weight change how long it takes?
It changes the peak you reach, not the rate you clear it. A heavier person reaches a lower peak from the same drinks and therefore needs fewer hours, but the hourly rate is about the same.
Every figure on this page is an estimate from an average body. Your own reading can be higher.