Blood alcohol level charts can help people estimate how much alcohol may be in their bloodstream after drinking.
A person’s blood alcohol content can vary based on several factors, including age, sex, and the number of drinks they consume.
This article reviews what blood alcohol content is and why it is important. It also includes charts showing different blood alcohol levels based on sex, weight, and number of drinks.
Blood alcohol content (BAC) is the percentage of alcohol in a person’s bloodstream after drinking alcohol. A person can typically measure it within 30–70 minutes of drinking.
The number of drinks a person has, along with their weight and sex, can affect their BAC levels.
The higher the percentage of alcohol in the blood, the higher the level of intoxication.
While many believe home remedies, such as a cold shower or coffee, will help them become sober, time is the only way to reduce blood alcohol levels.
On average, a person’s BAC levels will decrease by about .015% every hour after starting to drink.
Why is it important?
Law enforcement can use BAC to determine if a person is sober enough to drive an automobile or operate heavy equipment safely.
In most states, the legal limit is .080 BAC, meaning anything over this number indicates a person is too intoxicated to drive.
As a person’s BAC level goes up, they may experience worsening symptoms of impairment or intoxication. At about .200, a person may experience blackouts. Levels over .300 typically cause unconsciousness, and breathing can stop at .450.
Blood alcohol level charts can help a person understand their BAC levels based on factors such as:
- sex
- weight
- number of drinks
- type of drink
- age
- liver health
- use of other medications or recreational drugs
- empty stomach
- body fat percentage
Experts calculate BAC in grams per 100 milliliters of blood. In other words, a BAC level of 0.05 means the person’s blood is 0.05% alcohol by volume.
The following charts show different blood alcohol levels based on sex, weight, and number of drinks.
| Male | 100 lb body weight (BW) | 120 lb BW | 140 lb BW | 160 lb BW | 180 lb BW | 200 lb BW | 220 lb BW | 240 lb BW | Legal impairment |
|---|---|---|---|---|---|---|---|---|---|
| 0 drinks | .00 | .00 | .00 | .00 | .00 | .00 | .00 | .00 | none |
| 1 drink | .04 | .03 | .02 | .02 | .02 | .02 | .02 | .02 | driving skills impaired — possible legal issues |
| 2 drinks | .08 | .06 | .05 | .05 | .04 | .04 | .03 | .03 | as above |
| 3 drinks | .11 | .09 | .08 | .07 | .06 | .06 | .05 | .05 | as above |
| 4 drinks | .15 | .12 | .11 | .09 | .08 | .08 | .07 | .06 | legally intoxicated — cannot operate cars or heavy equipment, criminal penalties |
| 5 drinks | .19 | .16 | .13 | .12 | .11 | .09 | .09 | .08 | as above |
| 6 drinks | .23 | .19 | .16 | .14 | .13 | .11 | .10 | .09 | as above |
| 7 drinks | .26 | .22 | .19 | .16 | .15 | .13 | .12 | .11 | as above |
| 8 drinks | .30 | .25 | .21 | .19 | .17 | .15 | .14 | .13 | as above |
| 9 drinks | .34 | .28 | .24 | .21 | .19 | .17 | .15 | .14 | as above |
| 10 drinks | .38 | .31 | .27 | .23 | .21 | .19 | .17 | .16 | as above |
| Female | 100 lb body weight (BW) | 120 lb BW | 140 lb BW | 160 lb BW | 180 lb BW | 200 lb BW | 220 lb BW | 240 lb BW | Legal impairment |
|---|---|---|---|---|---|---|---|---|---|
| 0 drinks | .00 | .00 | .00 | .00 | .00 | .00 | .00 | .00 | none |
| 1 drink | .05 | .04 | .03 | .03 | .03 | .02 | .02 | .02 | driving skills impaired — possible legal issues |
| 2 drinks | .09 | .08 | .07 | .06 | .05 | .05 | .04 | .04 | as above |
| 3 drinks | .14 | .11 | .10 | .09 | .08 | .07 | .06 | .06 | as above |
| 4 drinks | .18 | .15 | .13 | .11 | .10 | .09 | .08 | .08 | legally intoxicated — cannot operate cars or heavy equipment, criminal penalties |
| 5 drinks | .23 | .19 | .16 | .14 | .13 | .11 | .10 | .09 | as above |
| 6 drinks | .27 | .23 | .19 | .17 | .15 | .14 | .12 | .11 | as above |
| 7 drinks | .32 | .27 | .23 | .20 | .18 | .16 | .14 | .13 | as above |
| 8 drinks | .36 | .30 | .26 | .23 | .20 | .18 | .17 | .15 | as above |
| 9 drinks | .41 | .34 | .29 | .26 | .23 | .20 | .19 | .17 | as above |
| 10 drinks | .45 | .38 | .32 | .28 | .25 | .23 | .21 | .19 | as above |
Most states set the legal limit of BAC at .08% for both males and females. Lower-weight people may reach that level after about two drinks, while heavier people may not reach the level until about four drinks.
These values are estimates only. A person’s BAC may rise faster or slower depending on their unique body chemistry.
A person should consider getting a ride home if they intend to drink two or more drinks.
There are three ways to measure BAC:
- breathalyzer
- urine test
- blood test
Though police officers often use breathalyzers during traffic stops, and they are typically accurate, several things can affect their results, including:
- human error
- other compounds in the breath
- temperature
- how much air a person exhales
In some states, a court may require additional blood or urine testing to convict a person of driving under the influence (DUI).
The following are some common questions about blood alcohol levels.
What is a .20 alcohol level?
When a person reaches .20 BAC levels, they are significantly impaired. They cannot drive a car and may vomit, feel confused or dazed, and experience balance and coordination issues. Choking and blackouts can also be an issue at this level of intoxication.
What is a .30 alcohol level?
At .30 BAC levels, a person will likely lose consciousness. They will also experience several other symptoms, such as:
- impaired judgment and reflexes
- inability to remember things
- coordination and movement issues
- slowed reaction time
- vomiting
How many drinks is a 0.25 BAC?
The number of drinks it takes to reach a 0.25 BAC level varies from person to person. In general, it can take about 6–8 drinks to reach this level.
BAC is the percentage of alcohol a person has in their bloodstream. The higher the percentage, the more intoxicated and impaired a person becomes.
In most states, once someone reaches 0.08, they legally cannot drive.
Past this point, a person will continue to experience worsening symptoms and may pass out or even die from alcohol poisoning.
The blood alcohol level chart is an estimate only. Several factors, including age and body fat, can affect BAC levels.