Waking up and wondering when you will sober up is the right question to ask, because feeling fine and being at zero are different things. Sleep hides impairment well. The estimator above does the morning-after math: what you drank, when you stopped, and how fast bodies like yours clear alcohol, as a range rather than a false promise.
The morning-after math, in one paragraph
Your liver clears alcohol at a near-constant rate: on average about 0.015 percentage points of BAC per hour, with a published range of roughly 0.012 to 0.020 across healthy adults.2 That is close to one US standard drink per hour, no matter what you eat, drink, or regret in the meantime. How high you peaked depends on how much alcohol went in and how much body water it dissolved into, which is what the Widmark formula estimates from your weight and sex.3
Two honest consequences follow. First, heavy nights take much longer to clear than people assume: ten drinks can mean alcohol in your blood into the afternoon. Second, no formula knows your body, so the only honest output is a window. Every assumption is written down here.
Worked examples, straight from the engine
Four realistic nights, run through the exact model behind the calculator above. The window is hours from the last drink until BAC likely reaches zero; the later number is the one to plan around.
| Night | Drinks | Person | Likely zero after |
|---|---|---|---|
| Two beers with dinner | 2 × 330 mL beer | 70 kg woman | 3 to 7 hours |
| A steady pub evening | 4 pints of beer | 80 kg man | 6 to 14 hours |
| Wine with a long dinner | a bottle of wine | 65 kg woman | 9 to 20 hours |
| A heavy night | 3 beers, 2 glasses of wine, 4 shots | 85 kg man | 9 to 20 hours |
Stopped at midnight, "a heavy night" here may not clear until the following evening. That is not the calculator being dramatic; it is arithmetic.
What this site will not do
- No single-number BAC. A point value would claim precision the science does not have. Every result here is a range, and the headline is the conservative edge.
- No green lights. Nothing on this site will ever tell you that you are fine, cleared, or good to drive. The muted colors are deliberate.
- No "how many more can I drink" mode. This tool only looks backward at drinks already drunk. A forward-planning drinking calculator is a product decision with a body count, so it does not exist here.
Frequently asked questions
How do I know if I am still drunk the morning after?
You often cannot tell from how you feel. Sleep masks impairment: after a heavy night you can wake up feeling merely tired while your blood alcohol is still well above zero. The arithmetic is unforgiving, because your liver clears roughly one US standard drink per hour and nothing speeds that up. This calculator turns what you drank and when you stopped into an honest window for when your BAC likely reaches zero.
Can I still be drunk after 8 hours of sleep?
Yes. Eight hours of sleep removes at most the alcohol that eight hours of elimination can remove, roughly 6 to 10 US standard drinks worth for most adults, and less for smaller bodies. After a genuinely heavy night, waking up with alcohol still in your blood is normal, common, and exactly the situation this site exists for.
When will I sober up?
On average, blood alcohol falls by about 0.015 percentage points per hour, but the honest published range across healthy adults runs from roughly 0.012 to 0.020 per hour, and how high you peaked depends on your body as well as your drinks. That is why this calculator gives a window rather than a time, and why the later edge of the window is the one to plan around.
Does coffee, a shower, or food sober you up faster?
No. Caffeine makes you a more alert person with the same BAC, cold water makes you a colder one, and food only matters before or while you drink, when it slows absorption. Once alcohol is in your blood, your liver clears it at its own fixed pace and nothing sold, brewed, or poured changes that.
How accurate is this calculator?
It is an estimate with a substantial margin of error, and it says so on the label. It uses the Widmark formula with published population ranges for body-water ratio and elimination rate, which is why every result is a range. It cannot know your liver, your genes, your medications, or exactly what the bar poured. Only a breathalyzer or a blood test measures actual BAC.
Is it safe to drive if the calculator says I am probably sober?
This calculator never says driving is safe, and no calculator can. Estimates cannot measure your blood, and impairment can outlast the number anyway. Never drive after drinking. If you are wondering whether you are sober enough to drive, the answer is no.
Related tools and answers
Pour size and ABV to standard drinks, including what one mixed drink really counts as.
How long does alcohol stay in your system?Blood, breath, urine, saliva, and hair: detection windows with sources.
How to sober upThe honest answer about coffee, cold showers, food, and time.
How these estimates workThe Widmark formula, every assumption, and every error source, cited.
Sources
- NIAAA. What is a standard drink?
- Jones, A.W. (2010). Evidence-based survey of the elimination rates of ethanol from blood. Forensic Science International.
- Norberg, Å. et al. (2003). Role of variability in explaining ethanol pharmacokinetics. Clinical Pharmacokinetics.
- Cederbaum, A.I. (2012). Alcohol metabolism. Clinics in Liver Disease.