How long does it take for the alcohol to be gone?
After a sociable evening, the same question comes up sooner or later: when am I actually sober again? The honest answer is — it takes longer than most people think, and you cannot speed it up. The body eliminates alcohol at a largely fixed pace, no matter what you do in between. In this article we explain how fast elimination really is, why none of the well-known tricks work and how to estimate your rough remaining time. For a first orientation, the <a href="/en/blood-alcohol-calculator">blood alcohol calculator</a> helps.
The body eliminates around 0.1 to 0.15 per mille per hour
Most of the alcohol — about 90 to 95 percent — is broken down by the liver. A small remainder leaves the body through breath, sweat and urine. The key point is this: elimination is almost linear, that is, at roughly constant speed, regardless of how high the level currently is. As a rule of thumb, blood alcohol concentration falls by about 0.1 to 0.2 per mille per hour, on average around 0.15 per mille. Women and men barely differ in elimination speed — the difference lies mainly in absorption, not in elimination.
That sounds like little, but it adds up. Someone who reaches a peak of 1.0 per mille in the evening needs, at 0.1 per mille per hour, around ten hours to return to zero. Even at the more optimistic rate of 0.15 per mille it is still almost seven hours. So the alcohol keeps working inside you for half the night, long after you have fallen asleep.
Why elimination cannot be sped up
The speed of elimination is set by the capacity of your liver, and it works at its own rhythm. Neither coffee nor cold showers, fresh air, exercise or a greasy meal change that rhythm. All of these are persistent myths.
Coffee, for instance, makes you more alert because the caffeine masks tiredness — the alcohol level is completely unaffected. That is actually treacherous: you feel fitter than you are and overestimate yourself. A cold shower wakes up the circulation but lowers not a single per mille. Movement and sweating excrete only a vanishingly small part of the alcohol. And eating only helps before or during drinking, because a full stomach slows absorption — once the alcohol is in the blood, eating afterwards does nothing.
What actually influences the pace
There are individual differences, but they lie outside your short-term control. People who regularly drink heavily tend to eliminate a little faster because their liver is used to it — a dubious advantage bought at the price of health damage. Body composition, daily condition, medication and liver disease also play a role. For the individual case this can hardly be predicted, which is why every calculation remains only a rough approximation.
How to roughly estimate your remaining time
To estimate how much longer it will take, you need two things: your approximate peak value and the elimination rate. The <a href="/en/blood-alcohol-calculator">blood alcohol calculator</a> estimates the peak from your drinks, weight and sex using the Widmark formula. Dividing this value by the elimination rate gives you the approximate number of hours until sobriety.
An example: at an estimated peak of 0.8 per mille and a cautious elimination rate of 0.1 per mille per hour, it takes around eight hours for the value to reach zero. To be safe, always calculate with the lower elimination rate — then you are on the safe side and do not underestimate the duration. The calculator also shows you when you mathematically fall back below 0.5 and 0.3 per mille.
Why this is only an estimate
As useful as these rules of thumb are, they do not replace a measurement. Actual elimination varies individually, and even the starting value is uncertain. That is why the <a href="/en/blood-alcohol-calculator">blood alcohol calculator</a> cannot and must not make any statement about whether you are fit to drive. It does not replace a breath or blood test. Always allow a generous safety margin and never rely on a calculation to the minute.
Conclusion
Alcohol leaves the body slowly and at its own pace: around 0.1 to 0.15 per mille per hour, and no faster. Coffee, cold showers and fresh air make you more alert but not more sober. Only time lowers the value. Anyone planning to drive the next day should calculate generously — and when in doubt, leave the car where it is.