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BAC estimator

This BAC estimator uses the Widmark formula to estimate blood alcohol content from drinks, weight, sex, and time. It is an educational estimate only, never legal advice and never a guide to driving.

BAC estimator

Widmark formula. Estimate only, never legal advice.

Estimated BAC
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Enter drinks, weight, and time.

Status
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Sober in about
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Widmark formula: BAC% = grams of alcohol / (weight in grams x r) x 100 - 0.015 x hours. r = 0.68 men, 0.55 women. ESTIMATE ONLY: food, pace, meds, and body composition shift real BAC. Never drive after drinking.
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The Widmark formula

It divides grams of alcohol by body water (weight x a sex based ratio r: 0.68 for men, 0.55 for women), then subtracts 0.015% per hour for liver metabolism. One standard drink here means 10 g of pure alcohol, about a small beer or a single shot.

Why it is only an estimate

Food, drinking pace, medications, body composition, and tolerance all move real BAC away from the formula. Legal limits also vary by country. If you drank, do not drive, regardless of what any calculator says.

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BAC Estimator FAQs

What is a standard drink?
Here, 10 g of pure alcohol: roughly 285 ml of regular beer, 100 ml of wine, or 30 ml of spirits. Counts vary by country, so check your local definition.
How long until I am sober?
The liver clears about 0.015% BAC per hour, shown in the results. Only time sobers you up; coffee, food, and cold air do not speed it.
Why do women reach higher BAC than men?
Lower average body water per kg means the same alcohol concentrates more. The Widmark ratio r captures this: 0.55 vs 0.68.
Can I use this to decide if I can drive?
No. Never. It is an educational estimate with wide error bars, and impairment starts well below legal limits. Arrange another way home.
Does food lower BAC?
Food slows absorption, flattening the peak, but the total alcohol still processes at the same hourly rate. It delays, not reduces.
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