BAC (Blood Alcohol Content) Calculator
Estimate your blood alcohol content based on weight, gender, number of drinks, and time spent drinking.
Always drink responsibly.
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Estimated BAC
Blood Alcohol Content (BAC) is estimated using the Widmark formula:
BAC = (Alcohol Consumed in grams / (Body Weight in grams × r)) - (0.015 × Hours)
Where r is the Widmark factor:
- Male: 0.68
- Female: 0.55
One standard drink contains approximately 14 grams of pure alcohol:
- 12 oz beer (5% ABV)
- 5 oz wine (12% ABV)
- 1.5 oz spirits (40% ABV)
BAC Levels:
- 0.02% — Slight relaxation
- 0.05% — Reduced inhibitions
- 0.08% — Legal limit in most US states
- 0.10%+ — Significant impairment
Weight units:
- If using lbs, the formula converts to kg by dividing by 2.205
- If using kg, the weight is used directly
DISCLAIMER: This is an estimate only. BAC depends on many individual factors including metabolism, food intake, medications, and tolerance. Never drive after drinking. When in doubt, do not drive.