ganak.appBAC Calculator
Free BAC calculator using the Widmark formula. Estimate your blood alcohol content by weight, gender, and drinks consumed. See your current BAC, peak BAC, time to sober, impairment level, and an interactive timeline chart. Includes standard drink calculator, effects at each BAC level, and legal limits.
Food slows alcohol absorption and lowers peak BAC
Beer
12 oz · 5% ABV
estimated BAC
Slight euphoria, relaxation, and lowered inhibitions. Minimal impact on motor skills.
Peak BAC
0.042%
Std. Drinks
2.0
Time to Sober
1 hr 48 min
Impairment & Effects
Current impairment level and expected effects at your BAC
Slight euphoria, relaxation, and lowered inhibitions. Minimal impact on motor skills.
BAC Levels & Impairment
Standard impairment stages and their effects at each BAC range
No apparent impairment
Slight euphoria, relaxation, lowered inhibitions
Reduced coordination, impaired judgment
Blurred vision, loss of balance, legally intoxicated
Severe motor impairment, risk of alcohol poisoning
Risk of coma, respiratory failure, and death
This calculator is for educational purposes only. It provides estimates based on the Widmark formula with standard metabolic assumptions. Actual BAC varies based on individual physiology. Never use a BAC estimate to determine whether you are safe to drive. When in doubt, do not drive.
BAC Over Time
Estimated blood alcohol elimination timeline at 0.015% per hour
What is BAC?
Understanding Blood Alcohol Content
Blood Alcohol Content (BAC) measures the amount of alcohol in your bloodstream, expressed as a percentage. A BAC of 0.08% means there are 0.08 grams of alcohol per 100 milliliters of blood.
In all 50 US states, a BAC of 0.08% or higher is considered legally intoxicated for drivers 21 and older. Commercial drivers face a stricter limit of 0.04%, and most states enforce zero tolerance (0.00–0.02%) for drivers under 21.
BAC is the standard measure used by law enforcement, medical professionals, and forensic toxicologists to assess alcohol intoxication levels.
How BAC is Calculated (Widmark Formula)
The gold standard in forensic toxicology
This calculator uses the Widmark formula, first published in 1932 and still the most widely used method for estimating blood alcohol content:
Total fluid oz of pure alcohol consumed
Body weight in pounds
Widmark factor (0.73 male, 0.66 female) — body water distribution
Conversion constant from oz to grams of alcohol
Average alcohol elimination rate per hour
Hours since first drink
Our calculator also adjusts for stomach status: food slows alcohol absorption, reducing peak BAC by approximately 15–30%.
Factors That Affect BAC
Why the same amount of alcohol affects people differently
Body weight
Larger bodies contain more water, which dilutes alcohol and results in a lower BAC at the same consumption level.
Biological sex
Women generally have a higher proportion of body fat and less body water than men of the same weight, leading to higher BAC from the same amount of alcohol.
Food in stomach
Eating before or while drinking slows absorption, reducing peak BAC by 15–30%. Eating after drinking does not lower existing BAC.
Rate of consumption
Drinking faster overwhelms the body's ability to metabolize alcohol, causing BAC to rise more steeply.
Drink type & strength
Higher ABV drinks deliver more alcohol per volume. A standard drink contains approximately 0.6 oz of pure alcohol.
Medications
Many medications interact with alcohol and can amplify its effects, sometimes dangerously.
Liver & genetics
Individual differences in alcohol dehydrogenase enzyme activity affect how quickly alcohol is metabolized.
BAC Levels and Their Effects
How increasing BAC affects your body and behavior
| BAC | Level | Typical Effects |
|---|---|---|
| 0.00–0.019% | Sober | No apparent effects |
| 0.02–0.039% | Subtle Effects | Slight euphoria, relaxation, mildly lowered inhibitions |
| 0.04–0.079% | Mildly Impaired | Reduced coordination, impaired judgment, slower reactions |
| 0.08–0.149% | Significantly Impaired | Blurred vision, slurred speech, loss of balance, legally intoxicated |
| 0.15–0.299% | Severely Impaired | Severe motor impairment, nausea, blackouts, risk of poisoning |
| 0.30%+ | Life-Threatening | Loss of consciousness, coma, respiratory failure, risk of death |
Legal BAC Limits Around the World
Legal driving limits vary significantly by country
Many jurisdictions apply lower limits for commercial drivers, new drivers, and drivers under the legal drinking age.
Myths About Sobering Up
Common misconceptions that can be dangerous
The only thing that lowers BAC is time. Your body eliminates alcohol at approximately 0.015% per hour — and nothing can speed that up.
Frequently Asked Questions
Common questions about BAC and blood alcohol content