BAC Blood Alcohol Calculator
BAC Calculator
Personal Information
Affects body water content calculation
Alcohol metabolizes at ~0.015% per hour
Alcohol Consumed
Size: 12oz/330ml bottle
Size: 5oz/150ml cup
Size: 1.5oz/50ml shot
Size: 250ml custom
Enter your information and drinks consumed to calculate BAC
Blood Alcohol Content (BAC) measures the percentage of alcohol in your bloodstream. This calculator estimates your BAC based on drinks consumed, body weight, sex, and time elapsed. It is provided for educational purposes only. Never use a BAC estimate to decide whether it is safe to drive. Only time eliminates alcohol from your system.
See also:
How BAC Is Calculated
The Widmark formula is the most widely used BAC estimation method. It accounts for the amount of alcohol consumed, body weight, and a sex-based distribution factor (r) that reflects differences in body water content. The liver metabolizes alcohol at a fairly constant rate of about 0.015% BAC per hour.
BAC = (Alcohol in grams / (Body Weight in grams × r)) × 100 r = 0.68 for males, 0.55 for females Elimination: BAC decreases by ~0.015% per hour
One standard drink = 14g of pure alcohol (12 oz beer at 5%, 5 oz wine at 12%, 1.5 oz spirits at 40%).
BAC Effects by Level
Different BAC levels produce different effects. Individual sensitivity varies based on alcohol tolerance, medications, food consumption, fatigue, and other factors. Legal driving limits in the U.S. are 0.08% BAC for adults. Even at lower levels, judgment and reaction time are impaired.
| BAC Level | Typical Effects |
|---|---|
| 0.02-0.04% | Relaxation, slight euphoria, minor judgment changes |
| 0.05-0.07% | Impaired judgment, reduced coordination, lowered inhibitions |
| 0.08-0.10% | Legally impaired in most US states, impaired balance and reaction |
| 0.11-0.15% | Clear impairment of speech, vision, and coordination |
| 0.16-0.30% | Confusion, nausea, potential blackout |
| 0.31%+ | Potentially fatal, respiratory depression risk |
Frequently Asked Questions
Can I sober up faster with coffee or cold showers?⌄
No. Coffee and cold showers make you feel more alert but do not reduce your BAC or level of impairment. Only time allows your body to metabolize alcohol. The liver processes approximately one standard drink per hour. There is no shortcut.
Why do women have higher BAC than men after the same amount of alcohol?⌄
Women typically have a lower body water percentage than men of the same weight, meaning alcohol is more concentrated in a smaller volume of fluid. Women also produce less alcohol dehydrogenase (the enzyme that breaks down alcohol). As a result, the same amount of alcohol results in higher BAC and longer effects in women.
How long does alcohol stay in your system?⌄
For BAC purposes, alcohol is eliminated at roughly 0.015% per hour. A BAC of 0.08% would be fully eliminated in about 5-6 hours. However, certain tests (breath, urine, hair) can detect alcohol presence longer after drinking has stopped, as metabolites remain even after BAC returns to zero.
Does food affect BAC?⌄
Eating before and during drinking significantly slows alcohol absorption. Food in the stomach, especially fat and protein, delays the movement of alcohol into the small intestine where most absorption occurs. This reduces peak BAC and slows the rate of intoxication, though the total alcohol consumed is eventually absorbed.