Blood Alcohol Content Calculator (BAC)
Blood alcohol calculator: estimated BAC from the number of standard drinks, body weight, sex and time since drinking (Widmark formula).
BAC = AW · r − 0.015 · t
How to use this calculator
- Type your input in the box.
- The result updates as you type.
- Use “Copy result” or “Copy link” to share it.
A standard US drink contains 14 g of alcohol: 12 oz of beer, 5 oz of wine or 1.5 oz of spirits. The body removes roughly 0.015 % BAC per hour.
This is a rough estimate; real BAC depends on food, medication and metabolism. Never use it to decide whether you can drive — if you drink, don’t drive.
Frequently asked questions
3 drinks, 170 lb man, after 2 hours?
About 0.05 % BAC.
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