Your approximate blood alcohol concentration and how long it will take for your body to clear it.
Checked by the editorial teamRates and formulas: September 202618+
In your blood now, approximately—
Pure alcohol consumed—
Peak was about—
Until fully eliminated—
This is a rough estimate, not a breathalyser reading. The actual elimination rate depends on your liver, food, medication, sleep and how you feel, and can differ several times over. Do not drive after drinking alcohol.
This section is for people aged 18 and over.
The Widmark formula
The calculator uses a formula proposed by the Swedish chemist Erik Widmark. It estimates blood alcohol concentration from the amount of pure alcohol consumed and body weight:
C = A / (m × r) − β × t
A — pure alcohol, g: volume (ml) × strength (%) / 100 × 0.79
m — body weight, kg
r — distribution factor: 0.7 for men, 0.6 for women
β — elimination rate, on average 0.15 ‰ per hour
t — time since you started drinking, h
Example. A man weighing 80 kg drinks 1 litre of 5% beer — that is 39.5 g of pure alcohol. Peak concentration: 39.5 / (80 × 0.7) ≈ 0.71 ‰. After 2 hours it is about 0.40 ‰, and the alcohol will be fully eliminated roughly 4.7 hours after he started drinking.
Why the result is only an estimate
Elimination rates vary from person to person — from 0.1 to 0.25 ‰ per hour, and can be lower with liver disease.
On a full stomach alcohol is absorbed more slowly, so the peak is lower and comes later.
The formula does not account for medication, tiredness, dehydration, age or genetics.
What the law says
In Russia, drivers are allowed a measurement tolerance of 0.16 mg/l in exhaled air or 0.3 g/l in blood. This is not a “permitted amount” — it is a margin for instrument error. Even a small amount of alcohol slows your reactions, so the only safe choice is not to drive on the day you drink, or afterwards until you have had a good night’s sleep.
This information is for reference only and does not constitute financial, tax or legal advice. Prepared by our editorial team, last checked: September 2026. Found an error? Write to us.
Frequently asked questions
How long does a bottle of beer take to wear off?
For a man weighing 80 kg, half a litre of 5% beer is eliminated in about 2–3 hours on average; for a woman weighing 60 kg, in 3–4 hours. But it can differ for any individual.
Can you speed up alcohol elimination?
No. Coffee, a cold shower or sorbents do not make your liver work faster — they only mask intoxication. Time, water and sleep are what help.
Can I use the calculator to decide whether to drive?
No. The result is an averaged estimate and can be off several times over. If you have been drinking, do not drive.
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