🍻 BAC Calculator

1. Enter the number of standard drinks consumed.
2. Enter your body weight in pounds.
3. Select your biological sex (affects body water percentage).
4. Enter the hours elapsed since your first drink.
5. Click Calculate to see your estimated BAC and time to sobriety.

What counts as one standard drink?

In the US, a standard drink contains 14 grams (0.6 ounces) of pure alcohol. This equals one 12-ounce beer at 5% ABV, one 5-ounce glass of wine at 12% ABV, or one 1.5-ounce shot of 80-proof (40%) spirits. Many cocktails and craft beers contain more than one standard drink per serving.

How accurate is this BAC estimate?

The Widmark formula provides a statistical average, not a precise measurement. Individual factors like metabolism rate, food intake, medication, fatigue and genetic variations can cause your actual BAC to differ by 20 percent or more. Never use this calculator to decide whether it is safe to drive. The only truly safe BAC for driving is zero.

Does coffee or food lower BAC?

No. Only time reduces your BAC, because the liver metabolises alcohol at a fixed rate of about 0.015 per hour. Coffee may make you feel more alert, but it does not reduce your BAC or improve your reaction time. Eating food before or while drinking slows the absorption of alcohol (so your peak BAC is lower), but it does not speed up elimination.

Why do women typically have higher BAC than men?

Women generally have a higher percentage of body fat and a lower percentage of body water than men of the same weight. Since alcohol dissolves in water, a higher fat-to-water ratio means the same amount of alcohol produces a higher concentration in the bloodstream. Women also have less of the enzyme alcohol dehydrogenase, which breaks down alcohol in the stomach.

The most important thing to understand about BAC is that it always decreases at the same rate: approximately 0.015 per hour, regardless of coffee, food, cold showers or exercise. This means that if your BAC is 0.12, it will take about 8 hours to reach zero, and there is nothing you can do to speed it up. Plan ahead: if you know you will be drinking, arrange a designated driver, use public transit or book a ride-share service before you start. Many people are surprised to learn that they are still over the legal limit the morning after a night of heavy drinking. If you must drive the next day, use a personal breathalyser or wait at least one hour per standard drink consumed. Be aware that tolerance (the feeling of being less affected by alcohol) does not mean your BAC is lower: a person with high tolerance may feel sober at 0.08 BAC, but their reaction time and judgment are still impaired, and they are still legally over the limit. The safest rule is simple: if you drink, do not drive.