What is your BAC after 1 beer?
Blood Alcohol Concentration (BAC) Calculator
Blood alcohol concentration (BAC) is a commonly used measure of alcohol intoxication, also known as drunkenness. It is typically expressed as a percentage of alcohol per volume of blood. For example, in the United States (US), a BAC of 0.08 (0.08%) would translate to 0.08 grams of alcohol per 100 mL of blood.
In the US, the legal limit for BAC when driving is 0.08%. Drivers who are over the age of 21 (the legal drinking age in the US), who have a BAC equal to or greater than 0.08%, can face penalties. Penalties for those under the age of 21 are stricter, but vary by state. For those under the age of 21, the legal limit ranges from 0.01% to 0.05%.
Alcohol and health
Alcohol consumption has a number of short-term, as well as long-term effects. Short-term effects include dehydration and intoxication, while more long-term effects can include changes in the metabolism of the liver and brain. Alcohol consumption can also result in alcoholism, which is generally described as the use of alcohol that results in problems with mental or physical health.
Many studies regarding the effects of alcohol on health have been performed. Although there are some studies that support the conventional wisdom that a glass of red wine a day can have potential health benefits, these claims have not been rigorously proven. While some people may experience certain health benefits as a result of consuming some alcohol daily, not all people will, and the benefits do not come without risk.
Although alcohol, in moderation, is not necessarily deleterious, and may even have some positive benefits, more recent studies recommend that alcohol should not be consumed for its potential health benefits. While light or moderate alcohol (~1 drink per day: 12 fl oz beer, 5 fl oz wine, 1.5 fl oz distilled spirits) drinkers can certainly remain healthy, and may experience some health benefits, it is not fully known whether these benefits are worth the potential risks, since the potential benefits are relatively small compared to the risks.
Some of the potential health benefits that light to moderate use of alcohol can provide include:
- Reducing the risk of developing and dying from heart disease
- Reducing the risk of ischemic stroke
- Reducing the risk of diabetes
Again, these are only potential benefits, and consuming any amount of alcohol may not necessarily result in these benefits. Also, even light to moderate drinking can increase the risk of certain cancers, and of course, driving while intoxicated can have many severe consequences.
Furthermore, drinking can lead to alcoholism, and heavy alcohol use has no health benefits. Heavy drinking, as defined by the Mayo Clinic, is having more than three drinks a day for women and men over 65, and more than four drinks per day, or more than 14 drinks a week for men younger than 65. Excessive drinking can result in serious health issues, including:
- Increased risk of certain cancers
- Sudden death as a result of pre-existing cardiovascular disease
- Heart muscle damage that leads to heart failure
- High blood pressure
- Liver disease
- Accidental serious injury or death
- Brain damage
Overall, a person should not begin drinking for potential health benefits. Those who already drink light to moderate amounts, who have not experienced negative health effects, can probably continue drinking moderately as long as they are not at risk for becoming heavy drinkers and continue to be healthy. Most importantly, a person should consult their doctor regarding their alcohol consumption to determine what is safe for their particular situation.
Effects by blood alcohol concentration
The degree of impairment caused by alcohol intoxication varies based on BAC, as shown in the table below. Impairments range from subtle effects that can only be detected with special tests at levels between 0.001-0.029%, to problems with concentration, reflexes, motor control, and more, including a serious possibility of death at 0.50% or more.
|0.001–0.029||Average individual appears normal||Subtle effects that can be detected with special tests|
Reduced sensitivity to pain
Possibility of nausea and vomiting
Gross motor control
Temporary erectile dysfunction
Anger or sadness
Partial loss of understanding
Possibility of stupor
|Severe motor impairment|
Loss of consciousness
Central nervous system depression
Loss of understanding
Lapses in and out of consciousness
Low possibility of death
|0.400–0.500||Severe central nervous system depression|
Possibility of death
Positional alcohol nystagmus
|>0.50||High possibility of death|
No online BAC Calculator should be used to determine an individuals fitness to drive. There are so many variables and factors that can affect a specific individuals BAC level at any given time that the only fail-safe and reliable way to calculate an individuals blood alcohol level at a precise moment in time is by blood analysis or a reliable and type approved breathalyser. This BAC calculator provides reliable estimates based on average biological values and scientific research and should be used for educational, research and information purposes only. If in doubt, use common sense and do not drive.
The Drinkdriving.org Blood Alcohol Calculator
The Drinkdriving.org BAC calculator is based on the widmark method of calculating blood alcohol content. The BAC calculator provides an accurate estimation of an individuals BAC at a certain period in time.
Like any other online BAC calculator it cannot provide results with 100% accuracy due to the many variables that come into play (see below) that can affect an individuals BAC level.
While the calculator takes into account gender, weight, drink amount, alcohol percentage and the period of time over which any alcohol has been consumed, it is based on the consumption of alcohol by an average healthy human being.
What is BAC — Blood Alcohol Content?
Blood alcohol content is a measure of the amount of alcohol present in a certain amount of blood. It is usually described as the amount of alcohol in mg per 100ml of blood. The maximum prescribed legal drink driving limit in England and Wales is 80mg/100ml blood or 0.08% and in Scotland it is 50mg/100ml blood or 0.05%.
The maximum BAC (blood alcohol content) limit in England & Wales is:
35 micrograms of alcohol per 100 millilitres of breath; or
80 milligrams of alcohol per 100 millilitres of blood or
107 milligrams of alcohol per 100 millilitres of urine
The maximum BAC (blood alcohol content) limit in Scotland is:
22 micrograms of alcohol per 100 millilitres of breath; or
50 milligrams of alcohol per 100 millilitres of blood or
67 milligrams of alcohol per 100 millilitres of urine
It is a criminal offence to drive with a blood alcohol level that exceeds the maximum prescribed legal limit.
Factors that Affect your BAC (Blood Alcohol Content)
Numerous factors can affect an individuals BAC, these include:
- The amount of alcohol a person consumes: the more alcohol a person drinks, the higher their BAC will become
- The speed at which a person consumes alcohol: the faster a person drinks, the faster their BAC will rise
- A person’s gender: alcohol is highly water soluble and a person’s BAC is directly proportional to their total body water content. Females generally have less water in their bodies than males, this means that a female who drinks exactly the same amount of alcohol as a male, in the same space of time, will generally have a higher BAC.
- A person’s weight: the more a person weighs usually means the more water they will have in their bodies. This means any alcohol ingested will produce a lower alcohol to blood ratio than that of a person weighing less. This is because the alcohol is «spread out» more «thinly«.
- A person’s fat/muscle content: fatty tissue does not absorb alcohol very well, alcohol will be absorbed a lot more into other tissues which are rich in water such as muscle. If two people weighing 90kg, one a tall thin person and the other a small fat person consumed the same amount of alcohol, the small fat person would usually have a higher BAC than the thin person.
- A person’s metabolism (the rate at which alcohol is processed and eliminated by the body): this can vary from person to person, however, the average person will usually eliminate 10ml of alcohol per hour. Heavy drinkers may have more active livers and can therefore usually eliminate more alcohol than average. People with liver disease may have less active livers and will therefore usually eliminate alcohol slower.
- Medication and the amount of food in the stomach: this can have an effect on the rate at which alcohol is absorbed into the body and subsequently eliminated.
- A person’s age: younger people tend to usually metabolise alcohol more quickly than older people.
REMEMBER THE ONLY 100% SAFE ALCOHOL DRIVING LIMIT IS 0
IF YOU INTEND TO DRINK ALCOHOL — STAY SAFE AND DONT DRIVE!!
Blood Alcohol Content (BAC)
Blood alcohol level (BAC), is the amount of alcohol in your blood that develops from drinking beverages that contain alcohol. Levels can range from 0% (no alcohol) to over 0.4% (a potentially fatal level).
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What is blood alcohol content (BAC)?
Blood alcohol content (BAC), also known as a blood alcohol level, is the amount of alcohol in your blood.
Alcohol (ethyl alcohol or ethanol) is the intoxicating ingredient found in beer, wine and liquor. When you drink a beverage that contains alcohol, your stomach and small intestines rapidly absorb the alcohol and enter it into your bloodstream. Alcohol is a toxin to your body, so your liver then metabolizes the alcohol to filter it out of your blood.
If you’re drinking faster than your liver can process the alcohol, your BAC increases and you may feel the effects of drunkenness, also called intoxication. In general, your liver can process about one alcohol-containing drink per hour. One drink is typically defined as 12 ounces of beer, 5 ounces of wine or 1.5 ounces of liquor. However, different beers and wines can contain different percentages of alcohol.
The amount of alcohol in your blood can vary based on several factors including:
- The amount of alcohol you’re drinking.
- How quickly you’re drinking.
- How much food you ate before drinking.
- Your age and weight.
What do different blood alcohol levels indicate?
Alcohol is a central nervous system depressant (it reduces stimulation in your central nervous system) and affects every organ in your body.
Here’s how different percentages of blood alcohol content (BAC) can affect you physically and mentally:
- BAC 0.0%: There’s no alcohol in your blood (you’re sober).
- BAC 0.02%: At this percentage, you may experience an altered mood, relaxation and a slight loss of judgment.
- BAC 0.05%: At this percentage, you may feel uninhibited and have lowered alertness and impaired judgment.
- BAC 0.08%: At this percentage, you may have reduced muscle coordination, find it more difficult to detect danger and have impaired judgment and reasoning.
- BAC 0.10%: At this percentage, you may have a reduced reaction time, slurred speech and slowed thinking.
- BAC 0.15%: At this percentage, you may experience an altered mood, nausea and vomiting and loss of balance and some muscle control.
- BAC 0.15% to 0.30%: In this percentage range, you may experience confusion, vomiting and drowsiness.
- BAC 0.30% to 0.40%: In this percentage range, you’ll likely have alcohol poisoning, a potentially life-threatening condition, and experience loss of consciousness.
- BAC Over 0.40%: This is a potentially fatal blood alcohol level. You’re at risk of coma and death from respiratory arrest (absence of breathing).
Some people can develop a tolerance to alcohol. This means that they may not feel the same physical and mental effects of alcohol drinking the same amount they used to drink. This doesn’t mean their blood alcohol content (BAC) is lower. It just means they experience the effects of alcohol differently.
When would I need a blood alcohol content (BAC) test?
People have BAC tests for a variety of reasons, including:
- Medical testing: Healthcare providers use BAC tests for diagnosing alcohol poisoning, a potentially life-threatening complication of consuming excessive amounts of alcohol in a short amount of time.
- Monitoringalcohol use disorder: If you’re in a treatment program for alcohol use disorder, they may have you undergo BAC tests while you’re in the program to see if you’re continuing to drink alcohol while in recovery.
- Workplace testing: Your employer may test for alcohol use if you’re a new applicant, regularly during employment and/or after an accident on the job.
- Legal testing: People may need to undergo a BAC test as a part of a legal investigation, such as in the case of underage drinking, monitoring for alcohol use while on parole and determining if a person is/was driving a vehicle while legally intoxicated.
Who performs a blood alcohol content (BAC) test?
A healthcare provider called a phlebotomist usually performs blood draws, including those for a blood alcohol content test, but any healthcare provider who is trained in drawing blood can perform this task. A provider then sends the samples to a lab where a medical laboratory scientist prepares the samples and performs the tests on machines known as analyzers.
What should I expect during my blood alcohol content (BAC) test?
You can expect to experience the following during a blood test, or blood draw:
- You’ll sit in a chair, and a healthcare provider will check your arms for an easily accessible vein. This is usually in the inner part of your arm on the other side of your elbow.
- Once they’ve located a vein, they’ll clean and disinfect the area.
- They’ll then insert a small needle into your vein to take a blood sample. This may feel like a small pinch.
- After they insert the needle, a small amount of blood will collect in a test tube.
- Once they have enough blood to test, they’ll remove the needle and hold a cotton ball or gauze on the site to stop the bleeding.
- They’ll place a bandage over the site, and you’ll be finished.
The entire procedure usually takes less than five minutes.
What should I expect after my blood alcohol content (BAC) test?
After a healthcare provider has collected your blood sample, they’ll send it to a laboratory for testing. Once the test results are back, the person or provider who ordered the test will share the results with you.
What are the risks of a blood alcohol content (BAC) test?
Blood tests are a very common and essential part of medical testing and screening. There’s very little risk to having blood tests. You may have slight tenderness or a bruise at the site of the blood draw, but this usually resolves quickly.
When can I expect my blood alcohol content (BAC) test results?
Depending on the reason for the BAC test, you may receive your results within a few hours to several business days.
Results and Follow-Up
What do the results of a blood alcohol level (BAC) test mean?
Your report may provide blood alcohol level test results in different ways depending on the laboratory that processes the test. The results are typically reported in the percentage of blood alcohol content (BAC) — for example, 0.03% BAC. They can also be listed as grams per milliliter (g/mL). This test result would be 0.03 g/100 mL.
The results may also indicate “positive” or “negative,” meaning you did have alcohol in your blood or you had no alcohol in your blood, respectively.
The timing of a BAC test can affect the accuracy of the results. A blood alcohol test is only accurate within six to 12 hours after your last alcohol-containing drink. If you have questions or concerns about your results, talk to your healthcare provider and/or a lawyer, depending on your situation.
Frequently Asked Questions
What is the legal blood alcohol level?
For most states in the United States, the alcohol limit to legally drive a vehicle for drivers aged 21 or older is currently 0.08% BAC. Utah’s legal limit is lower, at 0.05% BAC. Like all laws, these legal limits can change.
A note from Cleveland Clinic
In moderation, alcohol can be OK for people old enough to legally drink. However, if you drink excessive amounts of alcohol in a short amount of time and/or drink large amounts frequently, your health can be at risk. If you’re concerned about your drinking habits, reach out to your healthcare provider or a specialist. Together, you can come up with a plan to improve your habits and health.