If you are driving a car and are 21 years of age or older, you are considered to be driving under the influence if your blood alcohol concentration (BAC) is:

Under Idaho law, you are considered to be driving under the influence if you are 21 years of age or older and your blood alcohol concentration (BAC) is 0.08 percent or higher. If you are driving and your BAC is lower than 0.08 percent, you may still be convicted of driving under the influence if you have consumed other intoxicating substances.