Blood Alcohol Content (BAC) Calculator
Estimate your blood alcohol level and time to sober up
Important Disclaimer
This calculator provides estimates only. Actual BAC varies significantly between individuals. The only safe BAC for driving is 0.00%. Never drink and drive.
1 drink = 14g alcohol (12oz beer, 5oz wine, 1.5oz shot)
What is Blood Alcohol Content (BAC)?
What is Blood Alcohol Content (BAC)? Estimate your blood alcohol level and time to sober up
How It's Calculated
We use the Widmark formula, which considers your weight, gender, amount consumed, and time passed. Women typically have higher BAC than men after consuming the same amount due to differences in body composition.
Standard Drink
One standard drink contains approximately 14 grams of pure alcohol: 12 oz beer (5% ABV), 5 oz wine (12% ABV), or 1.5 oz distilled spirits (40% ABV).
BAC Levels and Effects
| BAC Level | Effects |
|---|---|
| 0.00% - 0.02% | Normal behavior, no impairment |
| 0.02% - 0.05% | Mild relaxation, slight impairment |
| 0.05% - 0.08% | Noticeable impairment, reduced coordination |
| 0.08% - 0.15% | Legal limit in many places, significant impairment |
| 0.15% - 0.25% | Severe impairment, potential blackouts |
| 0.25%+ | Dangerous, possible alcohol poisoning |
Legal BAC Limits
United States
Legal limit: 0.08%
Commercial drivers: 0.04%
Under 21: 0.01-0.02%
Legal limit: 0.05%
Legal limit: 0.05%
Some countries: 0.02%
Zero tolerance in some nations
Important: Important: Even below the legal limit, your driving skills are impaired. The safest choice is to never drive after drinking. Use a designated driver, rideshare, or public transportation.
Frequently Asked Questions
How accurate is this BAC calculator?
This calculator provides an estimate based on the Widmark formula, but actual BAC can vary significantly due to factors like individual metabolism, body composition, food consumption, medication, and genetics. The only way to know your exact BAC is with a breathalyzer or blood test. Treat this as an educational tool only.
Does eating food affect BAC?
Yes, eating food before or while drinking slows alcohol absorption, leading to a lower peak BAC than drinking on an empty stomach. However, food doesn't prevent impairment - it just delays it. The total amount of alcohol in your system remains the same.
How long does alcohol stay in your system?
The liver metabolizes alcohol at an average rate of about 0.015% BAC per hour (roughly one standard drink per hour). However, this varies between individuals. Coffee, cold showers, or vomiting won't speed up this process - only time can lower your BAC.
Why do women have higher BAC than men?
Women typically reach higher BAC levels than men after consuming the same amount of alcohol for several reasons: women generally have less body water (alcohol distributes into water), lower levels of the enzyme that metabolizes alcohol, and hormonal differences. This is why our calculator accounts for gender.
Can coffee or water sober me up?
No. Coffee, water, food, or cold showers may make you feel more alert, but they don't lower your BAC. Only time allows your liver to metabolize alcohol. The average person eliminates alcohol at a steady rate regardless of what they consume. Never rely on tricks to pass a BAC test or drive safely.
What are the legal consequences of drunk driving?
Consequences vary by jurisdiction but can include license suspension, heavy fines, jail time, increased insurance rates, and a criminal record. Beyond legal penalties, drunk driving can cause injuries or death to yourself and others. Always arrange alternative transportation if you've been drinking.