Calculate your Blood Alcohol Concentration (BAC) based on drinks consumed, body weight, gender, and time elapsed. Get instant results with detailed impairment level information.
| BAC (%) | Behavior | Impairment |
|---|---|---|
| 0.001–0.029 | Average individual appears normal | Subtle effects detectable with special tests |
| 0.030–0.059 | Mild euphoria, relaxation, talkativeness, decreased inhibition | Concentration impaired |
| 0.060–0.099 | Blunted feelings, reduced sensitivity to pain, euphoria | Reasoning, depth perception, peripheral vision, glare recovery |
| 0.100–0.199 | Over-expression, boisterousness, possible nausea and vomiting | Reflexes, reaction time, gross motor control, slurred speech |
| 0.200–0.299 | Nausea, vomiting, emotional swings, partial loss of understanding | Severe motor impairment, loss of consciousness, memory blackout |
| 0.300–0.399 | Stupor, central nervous system depression, lapses in consciousness | Bladder function, breathing, dysequilibrium, heart rate |
| 0.400+ | Severe CNS depression, coma, possibility of death | Breathing, heart rate - HIGH RISK OF DEATH |
Blood Alcohol Concentration (BAC) is a measure of alcohol intoxication used for legal and medical purposes. It is expressed as a percentage of alcohol per volume of blood. For example, a BAC of 0.08% means 0.08 grams of alcohol per 100 mL of blood.
In the US, 0.08% is the legal limit for drivers 21+. For those under 21, limits range from 0.01% to 0.05% depending on the state.
The body metabolizes alcohol at approximately 0.015% per hour. This rate cannot be accelerated by coffee, cold showers, or other methods.
Women generally have less body water than men, resulting in higher BAC levels for the same amount of alcohol consumed.
BAC levels above 0.40% can be life-threatening. Excessive drinking can lead to alcohol poisoning, requiring immediate medical attention.
This calculator provides estimates only. Individual metabolism varies. Never rely solely on calculators to decide if you're safe to drive.
A = Total alcohol consumed in grams
W = Body weight in grams
r = Gender constant (0.68 for men, 0.55 for women)
t = Time elapsed in hours
0.015 = Average alcohol metabolism rate per hour
A 180 lb (81.6 kg) male who consumed three 12 oz beers (5% ABV) over 2 hours:
Up to 1 drink per day for women and up to 2 drinks per day for men (1 drink = 12 fl oz beer, 5 fl oz wine, 1.5 fl oz spirits)
This calculator uses the Widmark formula, which is widely accepted. However, individual metabolism varies based on factors like food consumption, medications, and overall health. Use as an estimate only.
No. Coffee, cold showers, or exercise do not accelerate alcohol metabolism. The liver processes alcohol at a fixed rate of about 0.015% per hour.
In the US, it's 0.08% for drivers 21 and over. For those under 21, most states have "zero tolerance" laws with limits from 0.01% to 0.05%. Penalties for DUI can include fines, license suspension, and jail time.
Women typically have less body water than men of the same weight, resulting in higher BAC levels from the same amount of alcohol. The gender constant (r-value) accounts for this physiological difference.
BAC levels above 0.30% can be life-threatening and require immediate medical attention. Signs of alcohol poisoning include confusion, vomiting, seizures, slow breathing, and unconsciousness.
Food can slow alcohol absorption if eaten before or while drinking, but it does not lower BAC once alcohol is already in your bloodstream. Only time can reduce BAC levels.
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Transparency & trust
BAC is an estimate based on user-entered drink, body, sex, and elapsed-time assumptions; individual absorption and elimination vary substantially.
Reviewed by Jack Tao
Technical methodology reviewer
Full-stack developer with 10+ years of software engineering experience
This review checks implementation, formulas, units, edge cases, and alignment with the cited material. It does not represent independent medical or financial advice.
Important limitation
For educational information only. This estimate is not medical advice, a diagnosis, or a substitute for care from a qualified health professional.
Never use an estimated BAC to decide whether to drive or perform a safety-sensitive activity. Only an approved test can measure BAC.