In every state, it’s illegal—a “per se” DUI—to drive with a blood alcohol concentration (BAC) of .08% or more. (The BAC limit can be even lower for certain motorists, like commercial vehicle drivers and drivers younger than 21.) But everyone absorbs and metabolizes alcohol at different rates, and there are lots of factors that affect BAC. So there’s no exact formula for determining how many drinks equate to a given BAC level. Plus, you can be convicted of DUI for driving “impaired” (by alcohol or drugs) even if you were under the BAC limit.
The chart below gives BAC estimates that correspond to number of drinks consumed and body weight. (For another way of looking at blood-alcohol approximations, check out our BAC calculator.)
The BAC values in the chart below are only estimates. You shouldn’t rely on their accuracy when deciding whether to drive or do anything else. The chart doesn’t account for all the factors that can affect BAC levels or the extent of impairment—for example, fatigue, medications taken, amount of food consumed, or chugging versus sipping. If you’ve been drinking, it’s always best to let someone else drive.
|Weight||Number of Drinks|
In the chart, one drink equals 1.5 ounces of hard liquor, 12 ounces of beer, or five ounces of wine. For example, one ten-ounce glass of wine would count as two drinks.
Also, time is an important consideration in using the chart. The human body metabolizes alcohol over time. Generally, this metabolization reduces a person’s BAC by about .015% per hour. For example, someone with a BAC of .08% at 4:00 p.m. and stops drinking would likely have a BAC of about .05% two hours later at 6:00 p.m.
Everyone’s body reacts differently to alcohol. However, there’s certainly a correlation between a person’s BAC level and symptoms of intoxication. And these symptoms become more pronounced—and have an increasingly detrimental effect on driving ability—as BAC increases.
Follow the links below to find the DUI laws in your state.