Add your drinks and their timing to see estimated BAC over time and when the model may reach zero. This is a forecast, not confirmation that you are sober.
Absorption continues after a drink is finished. This model shows absorption and elimination together. Its peak and zero point are estimates, not measurements or confirmation of sobriety.
How does the BAC calculator work?
The calculator converts each serving’s volume and strength into an amount of pure alcohol, then models absorption and elimination minute by minute. Weight, sex, age, height and food are included. It uses the Cheers model with standard hydration and one shared absorption rate for all servings online.
Why is this only an estimate?
This is a mathematical model, not a breathalyzer measurement. Medicines, health, food and individual metabolism can change the actual result. Even 0.00 does not confirm sobriety. The estimate refers to the moment you press the button; entries and results are neither stored nor sent.
The calculator distinguishes three moments that are easy to confuse: the end of drinking, the estimated peak and the point at which the modelled curve reaches zero. None of them is an actual measurement or confirmation that you are fit to drive.
Since the last drink
This is only the time since you finished the serving. Alcohol may still be in the digestive tract and passing into the bloodstream.
Estimated peak
The highest point of the curve may occur after the last sip. Drinking pace, food and the order of servings affect where it falls.
Estimated time to zero
This is the mathematical point at which the model reaches 0.00. It does not confirm actual sobriety or fitness to drive.
Why can the result keep rising after you stop drinking?
The last sip does not end absorption. Some alcohol may still be moving from the stomach and intestines into the blood. At the same time, the body has already begun metabolising it, so the visible curve reflects two processes happening together.
Drinking several servings quickly can put a large amount of alcohol into the absorption phase at once. Food often slows this process, but it does not neutralise ethanol. That is why time since the last drink is not the same as time since the estimated peak.
Illustrative scenarios from the same model
The estimate is indicative and does not replace a breathalyser measurement.
1 beer, 500 ml · 5%2 h 23 minThe estimate is indicative and does not replace a breathalyser measurement.2 glasses of wine, 150 ml · 12%3 h 26 minThe estimate is indicative and does not replace a breathalyser measurement.3 servings over 3 hours5 h 38 minThe estimate is indicative and does not replace a breathalyser measurement.
The number of servings alone is not enough
Two “drinks” can contain completely different amounts of ethanol. A wine glass filled with 100 ml and the same glass filled with 200 ml are not the same serving. Likewise, a 4% beer and an 8% beer of the same volume differ twofold in alcohol content. You therefore need the volume, label strength and time of every serving; the result also depends on personal data and the model assumptions used.
What does not speed up alcohol elimination
Coffee
Caffeine may reduce drowsiness and create a sense of being more capable. It does not remove alcohol from the blood or automatically restore judgement and coordination.
A cold shower and fresh air
They may stimulate you or improve how you feel, but they do not increase the speed of the enzymes that metabolise ethanol.
Exercise
Movement does not “sweat out” a meaningful amount of alcohol. With impaired balance, dehydration or weakness, it may further increase the risk of injury.
Sleep and food
Sleep gives the body time, and food may affect absorption. Neither neutralises alcohol that has already been consumed.
How to read a time-to-zero estimate sensibly
1
Check the input data
The volume, strength and time of every serving should reflect what actually happened. An error in one strong drink can shift the entire curve.
2
Look at a range, not a minute
The modelled time is a guide. The body does not work with clockwork precision, so a single minute should not be treated as a safety boundary.
3
Allow for a further rise
If drinking ended recently, the estimated peak may still be ahead of you even when you feel stable.
4
Separate planning from driving
An estimate can help plan the night or morning, but a decision about driving requires a reliable measurement, knowledge of the law and a safety margin.
Common questions about sobering time
How long does alcohol remain in the blood?
There is no single value for every person and serving. The grams of ethanol, drinking times, absorption rate, body composition, model parameters and individual elimination rate all matter.
When will I be sober?
The chart can estimate when the model reaches zero. It is a forecast, not a measurement, so do not base a driving decision only on the app or on how you feel.
Can the result rise after drinking has ended?
Yes. Alcohol can continue to be absorbed after the last sip, so the estimated peak may occur later.
Does food shorten the time to zero?
Food may affect the rate of absorption, but it does not remove ethanol that has already been consumed. A meal should not be treated as a way to neutralise alcohol.
Does coffee or a cold shower change the result?
They may change perceived drowsiness or alertness, but they do not predictably accelerate alcohol metabolism or confirm sobriety.
