Question 1

What is a standard drink?

Accepted Answer

In the United States, a standard drink contains approximately 14 grams of pure alcohol. This is equivalent to 12 ounces of regular beer (5% ABV), 5 ounces of wine (12% ABV), or 1.5 ounces of distilled spirits (40% ABV). Other countries may define a standard drink differently, so check your local guidelines.

Question 2

How accurate is the Widmark formula?

Accepted Answer

The Widmark formula provides a reasonable estimate but is not perfectly accurate for any individual. It does not account for food in the stomach, rate of drinking, individual liver enzyme activity, medications, or health conditions. Actual BAC can vary by 20% or more from the estimated value. Never rely on this calculator to determine if you are safe to drive.

Question 3

How long does it take for alcohol to leave your system?

Accepted Answer

The body metabolizes alcohol at an average rate of about 0.015% BAC per hour. For example, if your BAC is 0.08%, it would take approximately 5.3 hours to reach 0.00%. This rate is relatively constant regardless of body size, though it can vary based on liver health, genetics, and other factors. There is no way to speed up alcohol metabolism.

Question 4

Why do women typically have higher BAC than men?

Accepted Answer

Women generally have a higher BAC than men of the same weight after consuming the same amount of alcohol. This is primarily because women typically have a lower proportion of body water (55% vs 68% in men), which means alcohol is distributed in a smaller volume of fluid. Women also tend to have lower levels of alcohol dehydrogenase, the enzyme that breaks down alcohol in the stomach.

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