Free Online Calculators
BAC & time until sober after drinks
This calculator estimates your peak blood alcohol concentration (BAC) and tells you how many hours it takes until you're fully sober. It uses the Widmark formula, factoring in your weight, sex and the drinks consumed, and the body's average burnoff rate of 0.15‰ (0.015% BAC) per hour. Great for planning ahead responsibly after a night out.
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Your liver breaks alcohol down at a roughly steady rate, so an ounce of pure alcohol takes considerably longer to clear than the time it took to drink it. The exact figure depends on your body weight, sex, and liver function, which is why an estimate should always be treated as a rough guide.
A single unit is cleared in about the time it takes your liver to metabolise it, which for most people is on the order of an hour, though slower in smaller people and those with reduced liver function. Units add up, so several drinks in an evening can keep alcohol in your blood well into the next morning.
A burnoff calculator estimates how long alcohol stays in your blood from the size and alcohol content of each drink, your body weight and sex. It adds up the pure alcohol, estimates your peak blood alcohol with the Widmark formula and divides it by a constant elimination rate, so the result is an estimate and not proof of sobriety or fitness to drive. Count the hours from your last drink.
There is no fixed number of days that "cleanses" the liver, but fat in the liver and raised liver enzymes typically improve within weeks of stopping alcohol. Regular alcohol-free days each week help more than occasional detox periods, and advanced scarring does not reverse fully.
Your body processes alcohol at a fairly predictable rate — roughly 0.15‰ per hour using the widely accepted Widmark formula. That means if your blood alcohol concentration (BAC) peaks at 1.2‰ after a few drinks, your body needs approximately 8 hours to bring it back to 0.0‰. This alcohol metabolism calculator takes the guesswork out of that math by asking you what you drank and giving you a clear answer: how many hours until you are sober again?
The Widmark formula accounts for your body weight and biological sex, because these factors directly affect how alcohol distributes through your body. A 90 kg man and a 60 kg woman drinking the same amount will reach very different peak BAC levels — and therefore very different "sober again" times. Knowing your actual numbers is far more useful than rough guesses like "I'll be fine after a few hours of sleep."
Let's say a 75 kg man has 3 beers (each 0.33 L at 5% ABV), about 39 g of pure alcohol. The calculator estimates his peak BAC at about 0.77‰. At a 0.15‰/h elimination rate, he would return to 0.0‰ in about 5 hours. If he had 5 beers instead, the peak rises to about 1.28‰, pushing the sober time out to about 8.5 hours.
For a 60 kg woman consuming the same 3 beers, her peak BAC would be noticeably higher — about 1.18‰ — because women generally have a lower body water percentage. That adds almost three hours: she needs about 7.9 hours to get back to 0.0‰. These differences are exactly why generic rules like "one drink per hour" can be misleading for so many people.
Using an alcohol burnoff calculator like this one on simple-calculator.online gives you a personalized estimate based on your own profile, not a one-size-fits-all average. It's a practical tool for planning your evening responsibly — whether you're deciding when it's safe to drive the next morning or simply curious about how your body handles alcohol.
This alcohol metabolism calculator is designed to give you a reliable estimate of your peak BAC and how long until sober based on the Widmark formula. However, real-world metabolism varies due to factors like food intake, hydration, fatigue, medication, liver health, and individual genetics. The 0.15‰/h elimination rate is a well-researched average, but some people metabolize faster or slower.
Never use this tool to decide whether you are legally safe to drive. Legal BAC limits vary by country, and even low BAC levels affect reaction time and judgment. The only way to know your actual BAC in real time is through a certified breathalyzer test.
The Widmark formula is widely used in forensic science and medical research. It provides a solid estimate, but individual factors like food consumption and metabolism speed can shift results by 20–30% in either direction.
No. Only time reduces your BAC. Coffee may make you feel more alert, but it does not speed up how long until sober — your liver processes alcohol at its own fixed rate regardless.
Yes. This tool is intended for informational purposes only and does not replace professional medical advice. If you have concerns about alcohol consumption or its health effects, consult a qualified healthcare professional.