How BAC Is Estimated
This calculator uses the Widmark formula, the most widely validated method in forensic and clinical toxicology:
BAC = (Alcohol in grams) ÷ (Body weight in grams × r) − (0.015 × hours elapsed)
Where r is the volume of distribution: 0.68 for men, 0.55 for women. Women have a lower value because higher average body fat holds less water—and therefore less alcohol—per kilogram.
BAC Effects Reference
| BAC Level | Typical Effects |
|---|---|
| 0.01–0.03% | Mild relaxation, slightly reduced inhibitions |
| 0.04–0.06% | Warmth, minor impairment of judgment and memory |
| 0.07–0.09% | Noticeably impaired balance and reaction time. Legal limit in US: 0.08% |
| 0.10–0.15% | Clear impairment of motor control, slurred speech |
| 0.16–0.30% | Severe impairment, possible blackout |
| 0.30%+ | Risk of alcohol poisoning, loss of consciousness |
Your body eliminates alcohol at roughly 0.015% per hour, regardless of food, water, caffeine, or cold air. Nothing speeds this up.