Maybe You
Shouldn’t Drive?
Calculate Your Blood Alcohol Concentration
View The BAC CalculatorThis is not intended as a scientific tool for measuring Blood Alcohol Concentration (BAC), but is rather designed to help adults of legal drinking age understand the factors that affect their BAC. The information presented should not take the place of your own responsible decisions about drinking alcohol, or about whether and when it will be safe for you to drive. The effects of alcohol vary among individuals because of many factors and may be different for the same person at different times. The BACs shown are solely for illustrative purposes, and do not reflect the interaction of alcohol with prescription, over-the-counter, or illegal drugs. Mixing any drug with alcohol can be dangerous to you and to others. You should never drink and drive.
Physical & Mental Impairment
Drinking even a slight amount of alcohol can impair your physical and mental faculties. The extent of impairment will depend on your blood alcohol concentration (BAC), or the percent of alcohol in your blood stream. Several factors contribute to a person's BAC, including:
Amount of Alcohol
You Consume
Time Period Over Which You Consume It
Your Weight and Biological Gender
Whether You Have Taken Medication
In every state, you are deemed to be legally impaired with a BAC of 0.08%, and you cannot drive. If you are a commercial driver, the legal limit is 0.04%. Most states also have “zero tolerance” laws. If you are under the legal drinking age of 21 in those states, you cannot drive with any trace of alcohol in your blood, or a BAC as low as 0.01%.
Of course, in our view, the only safe BAC level for driving is 0.00% – no matter who you are!
BAC Calculator
Here, for educational purposes only, we present a BAC Calculator. You can use the calculator and our chart to estimate how alcohol will affect you and your ability to drive. We base the calculator and chart on information provided by:
Calculate Your BAC:
Blood Alcohol Concentration
Mental & Physical Impairment
0.00 No impairment. This is the only safe BAC level for driving
Mental & Physical Impairment
0.01 - 0.03 Slight physical and mental effects such as mood elevation. In most states, it is illegal to drive with a BAC of 0.01% or higher if you are under age 21.
Mental & Physical Impairment
0.04 – 0.06 Relaxed feeling and slight impairment of memory, reasoning and attention. If you are a commercial driver, it is illegal to drive with a BAC of 0.04% or higher.
Mental & Physical Impairment
0.07 – 0.09 Noticeable impairment of speech, balance, vision and motor control. Significant impairment of driving skills. It is illegal to drive with a BAC of .08% or higher.
Mental & Physical Impairment
0.10 – 0.12 BAC will cause significant deterioration of judgment and motor control. Slurred speech and sleepiness may also be noticeable.
Mental & Physical Impairment
0.13 – 0.15 Gross physical impairment, including blurred vision and loss of balance. Anxiety and restlessness may start to kick in.
Mental & Physical Impairment
0.16 – 0.20 Vomiting and nausea. Dangerous impairment of reasoning.
Mental & Physical Impairment
0.21 – 0.30 Severe physical and mental impairment. Many will experience "blackouts."
Mental & Physical Impairment
0.30 – 0.40 Loss of consciousness and on the verge of coma.
Mental & Physical Impairment
0.41 – higher Coma is likely and risk of death due to respiratory failure.
What's a Standard Drink?
Beer
Amount: 12 oz.
ABV*: 4.5%
More: 16 oz. cup of beer = 1.4 drinks
Wine
Amount: 5 oz.
ABV*: 12%
More: 12 oz. glass of wine = 2.9 drinks
Cocktail
Amount: 1.5 oz.
ABV*: 40%
Cocktail (i.e. margarita) = 2-4 drinks
Physical & Mental Effects of Drinking Alcohol
| 0.00 | No impairment. This is the only safe BAC level for driving. |
| 0.01 - 0.03 | Slight physical and mental effects such as mood elevation. In most states, it is illegal to drive with a BAC of 0.01% or higher if you are under age 21. |
| 0.04 – 0.06 | Relaxed feeling and slight impairment of memory, reasoning and attention. If you are a commercial driver, it is illegal to drive with a BAC of 0.04% or higher. |
| 0.07 – 0.09 | Noticeable impairment of speech, balance, vision and motor control. Significant impairment of driving skills. It is illegal to drive with a BAC of .08% or higher. |
| 0.10 – 0.12 | Significant deterioration of judgment and motor control. Slurred speech and sleepiness may also be noticeable. |
| 0.13 – 0.15 | Gross physical impairment, including blurred vision and loss of balance. Anxiety and restlessness may start to kick in. |
| 0.16 – 0.20 | Vomiting and nausea. Dangerous impairment of reasoning. |
| 0.21 – 0.30 | Severe physical and mental impairment. Many will experience "blackouts." |
| 0.30 – 0.40 | Loss of consciousness and on the verge of coma. |
| 0.41 – higher | Coma is likely and risk of death due to respiratory failure. |