Driving limit
0.05%
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BAC Calculator (Blood Alcohol)
How many drinks puts you over the driving limit? This tool estimates BAC using the standard Widmark formula. For education only — never drink and drive.
One standard drink ≈ 14g pure alcohol (330ml beer / 150ml wine / 45ml spirits).
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Estimated BAC
Over the limit?
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Sober in approx.
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Peak BAC
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How the Widmark formula works
BAC = grams of alcohol ÷ (body water fraction × body weight in grams) − 0.015 × hours elapsed. The body metabolizes roughly 15mg% of alcohol per hour — about one standard drink per hour.
About the BAC (Blood Alcohol)
Estimate your blood alcohol content (BAC) from drinks consumed, body weight, and time elapsed. Uses the Widmark formula. The tool runs entirely in your browser, so nothing you enter is uploaded or stored.
How to use the BAC (Blood Alcohol)
- Body weight (kg) — your body weight in kg.
- Gender — select male or female.
- Standard drinks consumed — enter your standard drinks consumed.
- Hours since first drink — enter your hours since first drink.
Last updated
EDUCATIONAL USE ONLY. Never drive after drinking. Actual BAC varies by metabolism, food, medications, and health. This is not medical or legal advice.