BAC Chart
Interactive BAC reference chart showing estimated BAC levels by body weight and number of drinks. Includes effects at each BAC level and legal limits.
⚠️ Educational Tool Only — Never Drink and Drive
This calculator is for educational purposes only and provides estimates based on averages. Actual BAC depends on many individual factors. Never rely on a calculator to determine if you are safe to drive. If in doubt, don't drive. Call a rideshare, taxi, or designated driver.
How It Works
This chart displays estimated BAC values calculated using the Widmark formula for various combinations of body weight and number of standard drinks consumed within one hour. Each cell is color-coded: green (below 0.04%), yellow (0.04–0.079%), orange (0.08–0.149%), and red (0.15%+). The chart assumes standard drinks (14g of pure alcohol each) and no food intake. Use this as a general reference — your actual BAC will vary.
Frequently Asked Questions
What do the colors on the BAC chart mean?
Green (0.00–0.039%): Below impairment threshold. Yellow (0.04–0.079%): Some impairment, approaching legal limit. Orange (0.08–0.149%): Over legal limit, significant impairment. Red (0.15%+): Severe impairment, dangerous BAC level.
Does body weight really affect BAC?
Yes. Alcohol distributes through body water. Heavier individuals have more body water, so the same amount of alcohol produces a lower BAC. This is why a 200-lb person will have a lower BAC than a 120-lb person after the same number of drinks.
Why does gender affect BAC?
On average, women have a higher proportion of body fat and less body water than men of the same weight. Since alcohol distributes through body water, women typically reach a higher BAC than men of equal weight after consuming the same amount of alcohol.