BAC Facts: Impairment Starts at the First Drink
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Not sure if you’ve had too much alcohol? A blood alcohol level chart shows how much impairment begins as soon as you have a drink.
Alcohol affects everyone differently. Some people seem unfazed after a night of drinking, while for others, one glass can be enough to take away judgment and motor skills.
But just because you do not see the visible effects of alcohol, it doesn’t mean you aren’t impaired. As your blood alcohol concentration (BAC) rises, so does your loss of ability.
Blood alcohol level charts can help you understand the effects of drinking based on your weight and sex. The charts can also help you plan ahead if alcohol is on the menu.
The National Highway Safety Administration (NHTSA) uses BAC standard drink measurements of:
- 12-ounce beer
- 5-ounce table wine
- 1.5-ounce 80-proof liquor
Intoxication levels depend on how quickly you drink. Because of this, approximately 0.01% can be subtracted for every hour that passes between beverages.
The following charts show how your blood alcohol levels change as you consume alcohol.
As the current science has only been conducted on cisgender males and females, transgender or intersex individuals may be safer following the most conservative recommendations for their weight range.
Want a chart that tracks you as you go? Consider downloading a BAC app like DrinkControl or AlcoDroid for your phone.
Who you gonna call?
When it comes to driving, most U.S. states place the legal limit at 0.08% BAC (0.08 grams of alcohol per deciliter of blood), but alcohol doesn’t wait for 0.08% before it affects your functioning.
If you or a friend has consumed too much alcohol to safely operate a vehicle, you can arrange for a designated driver through national services like:
If you’re out at a bar, many facilities keep local listings on hand to help you arrange transport if you cannot do it yourself. Don’t be afraid to ask your server or bartender for assistance arranging a commercial driver ― they also want to make sure you get home safely.
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The symptoms of impairment can start as soon as you have a drink and may become worse the faster you drink.
| BAC level | Standard effects |
|---|---|
| 0.02 | • muscle relaxation • altered mood • increased body warmth • decline in visual function • diminished capacity to multitask • loss of judgment |
| 0.05 | • loss of fine motor control • exaggerated behavior • reduced coordination • lowered reaction time • impaired judgment • low alertness • heightened mood • lack of inhibition |
| 0.08 | • small and large motor function decline • poor hearing, seeing, speaking, and coordination • short-term memory loss • inability to concentrate • impaired perception • reduced cognitive processing speed |
| 0.10 | • noticeable lack of reaction time • slurred speech • slowed thinking • poor coordination |
| 0.15+ | • major loss of motor control • poor or no balance • severe attention and reaction deficits • inability to cognitively process sounds or visuals • nausea or vomiting |
Safety is the number one priority when it comes to drinking alcohol, and driving is just one well-known area of risk. Even when you’re at home, too much drinking can compromise your physical health, resulting in alcohol poisoning or death.
Understanding more about alcohol consumption can help you make the best choices when you drink.
What alcohol level is too high?
Determining when your alcohol level is too high depends on what you’re assessing it for.
Too high for driving, for example, is a number regulated by your state. This is usually 0.05% to 0.08% BAC . But that doesn’t mean it’s safe to drive if you’re below those numbers.
The National Institute on Alcohol Abuse and Alcoholism (NIAAA) states that any amount of alcohol is “too much” when you’re:
- pregnant
- under the legal drinking age
- planning on driving
- at an increased risk of alcohol-related cancers
- living with certain chronic medical conditions
- taking medications
If you’re wondering when alcohol becomes toxic to your system, a BAC of more than 0.40% can result in respiratory depression, coma, and even death.
Does 0.08 mean 8% alcohol?
A 0.08 BAC equals 0.08%, not 8%, alcohol volume.
BAC is measured by grams of alcohol per deciliter of blood, or per 100 milliliters (mL) of blood. This means for every 100 mL of blood, there are 0.08 grams of alcohol.
How many drinks is 0.08?
The point at which you reach 0.08% BAC depends on your sex, weight, how much you drink — and how quickly.
On average, for a 140-pound male, this is around 3 standard drinks. For a 140-pound female, it’s between 2 to 3 standard drinks.
Share on Pinterest Illustration by Ruth Basagiotia
What BAC level is good for you?
The verdict is in: no amount of alcohol is good for your health.
According to the World Health Organization (WHO) , “safe” alcohol consumption doesn’t mean there are health benefits. That glass of wine for dinner may have some antioxidants, but the benefits aren’t outweighing the negative impacts of alcohol on your body.
Changing your relationship with alcohol
Whether you want to find ways to politely decline drinking invitations, or are looking for guidance in kicking alcohol addiction, help is available.
You can find quitting resources by visiting:
- NIAAA Alcohol Treatment Navigator
- Alcoholics Anonymous
- Al-Anon
- Women for Sobriety