BAC Calculator

Blood alcohol content, or BAC, is an important number that helps determine the level of alcohol in a person’s bloodstream. The higher the BAC, the more alcohol is likely to have an impact on everything from coordination and balance to emotions and brain function.

Controlling your alcohol intake and watching your BAC levels can help prevent harm both to yourself and to others. To make tracking your BAC levels easier, consider using our BAC calculator below. A BAC calculator will help do the math for you, providing an estimate of your current blood alcohol content.

1. Number of Drinks:

2. What Are You Drinking?

3.Your Weight: (lbs)

4. How Long Have You Been Drinking?

Your Blood Alcohol Content* (BAC %):



How is BAC Determined?

Alcohol impacts your BAC in different ways, and can even impact various people differently. The most common way BAC is raised is through the number of drinks that a person consumes, on top of how many drinks you have and how quickly each drink is consumed in relation to each other.

Body weight can also play a role in determining BAC, as someone who weighs more has a higher water volume than someone who weighs less. This difference results in smaller people experiencing a greater impact from the same amount of alcohol ingested by larger people. Gender also impacts BAC, as women typically have a lower water volume in their bodies than men. To a lesser extent, recent food consumption, or the lack of food consumption, may also impact BAC.

How BAC Impacts the Body

Even a small amount of alcohol can impact both coordination and judgment when drinking, with each drink increasing your overall impairment. Too much alcohol and your body will ultimately shut down, resulting in organ failure and even death. It’s important to understand that individuals may react differently to alcohol intoxication at each BAC level. In general, they may exhibit some or all of the following symptoms and behaviors.

.02 BAC
At this level, the muscles start to relax. Inhibitions are also reduced, with many individuals experiencing a heightening of whatever mood they may have been in before they started drinking, whether that be a positive or a negative state of mind.

.05 BAC
Once you reach this level, you may start experiencing a mild euphoria. Your body temperature starts to feel elevated and your inhibitions become even more relaxed, along with an even greater exaggeration of mood.

.08 BAC
This is the legal BAC limit in many states including Texas , and typically for good reason. At this point you may think you’re not intoxicated, but your speech has started to slur, your ability to walk and stand starts to become more difficult and your reaction times slow. At this level of intoxication, motor skills are largely impacted and driving a car becomes dangerous (though for many, even at lower levels you should not be behind the wheel of a vehicle).

.10 BAC
At this level, your intoxication is more apparent both to yourselves and to those around you. Your judgement, memory, motor skills and balance are all reduced, and you start to forget just how many drinks you’ve had. Depending on the individual, you may become loud or belligerent. Men begin to experience difficulty achieving and maintaining an erection at this level.

.14 BAC
Once above .13, feelings of euphoria start to drop, and feelings of sickness, dizziness, and difficulty controlling the body take over. Each of the negative effects of drinking at lower alcohol concentrations are markedly more severe. At this point you may also start to black out.

.20 – .30 BAC
Alcohol sickness starts at this level, often resulting in vomiting. When this intoxicated, gag reflex is severely impacted, dramatically increasing the risks of choking on your own vomit. Blackouts are more frequent, and your memory starts to blackout as well. Pain sensors are dampened, which means that if you are injured at this point, you may not know it or feel the pain from it. This also reduces the chances you’ll go to get help.

.35 BAC
Once at .35, your blood alcohol level is similar to the effects of being under anesthesia. Your brain function is reduced, which also reduces your respiratory rate, causing you to potentially stop breathing.

.40 BAC
If you have not stopped breathing by this point, your body will most likely enter a coma state. Your heart rate will slow, and your chances of survival are very low.

Additional Consequences

Along with the physical consequences listed above, various potential social, financial and legal consequences may also occur with intoxication. For example, driving while intoxicated can not only injure you, but can also injure innocent people around you. In fact, an estimated 30 people die every day in the United States due to alcohol-related traffic accidents, according to the National Highway Traffic Safety Administration. Even if you survive the accident, or not even cause an accident at all, you may still be faced with fines and jail time for driving under the influence (DUI). Once you’re allowed to drive again, you may see additional penalties in the form of increased insurance rates and difficulty finding companies that will take the risk to insure you.

Driver Education Series:

Blood Alcohol Content Concentration and Alcohol Impairment

Safety is a requirement and responsibility on and off the roads. This is the reason why regulatory agencies and authorities put in place a number of road rules and regulations. For example, drivers are advised not to drink and drive, and authorities regularly track driver compliance through blood alcohol content (BAC). Here are some questions about BAC and alcohol impairment that every driver and commuter should know.

Question: Why check the ‘BAC’, and how is this measured?


      Blood alcohol content refers to the weight of alcohol in a specified volume of blood. Once a person drinks alcohol, this is immediately absorbed by the body through the walls of the small intestine and stomach and gets into the person’s blood stream.Once present in the bloodstream, alcohol can affect the person’s body and brain, and may impair one’s judgment and decision-making skills.

Within the 30 to 70 minutes after the last drink made by the person, the alcohol content in the person’s bloodstream can be measured.

Question: Are there specific types of alcohol or drinks that can drive the BAC?


    No, the type of drink does not matter. Once you drink your favorite spirit or beer, this will instantly get into your bloodstream. An average bar drink features 0.54 ounces of alcohol, and this is normally the content to expect from the following:

  • A 5-oz glass of wine
  • One 12-oz beer
  • One shop of distilled spirit

Question: What drives my BAC?


    There are a number of factors that can affect your BAC:

  • How many bottles and drinks did you have? Experts agree that the number of drinks can drive your BAC to crazy levels.
  • Male or female? Yes, your gender plays a crucial role in your BAC. Since women have more body fat and less water in the body, the alcohol gets into woman’s fat cells easily, driving more alcohol weight in the bloodstream.
  • Are you a fast drinker? Persons who consume alcohol faster will end up with higher BAC compared to the others who drink slowly.
  • Body weight. The amount of water in the body is directly proportional to weight. And if there is more water in the body, then it dilutes alcohol volume, thus lowering the BAC.
  • Got food in the stomach? Just like water, food in the stomach can also help lower BAC since food absorbs some of the alcohol.

Question: Can medications or other drugs affect BAC?


    The medications that you have taken will not affect your BAC. But there is a big chance that if you combine alcohol intake and medications, then it can affect judgment which can be risky when driving.

Question: What happens when I am impaired?


    It is difficult to assess the level or degree of impairment due to a number of factors. But according to some experts, just a small amount of alcohol can affect the brain, and change driving behavior. And the troubling thing is that many car owners and drivers will say that they are normal and think straight even if they are not. Now, this is a classic symptom of impairment- not realizing that alcohol is already clouding your judgment. The lower levels of impairment of the person may not be noticed by the other person, but for the driver, he will easily know where the ‘buzz’ starts. And there is a big chance that the driver is already impaired before he even knows it.

Question: Is there a way to know if I am already impaired, and why is this important?


      Alcohol will affect your driving behavior on and off the road. And the more alcohol you consume, the higher the chances that you will be at risk on the road. When it comes to signs of impairment, different drivers will showcase different signs.

According to experts, for the driver with a BAC that ranges from 0.08 and 0.10, he faces a high risk of getting involved in a single-vehicle crashes. He is 11 times more likely to get involved in an accident, more than a person with zero BAC, and this is even 52 times even greater for younger male drivers. Just a small amount of alcohol in the blood can affect one’s driving behavior.

Because of the risks involved, all states passed laws making it illegal for drivers to take their cars on and off the road if they manifest 0.08 in BAC or higher. State laws also recommend the arrest of drivers even if the BAC is below 0.80, if the attending law enforcement officer sees a probable cause that he is driving under the influence of alcohol.

Below is a chart that illustrates the common symbols that may be shown by drivers, with different BAC levels.

Blood Alcohol Concentration or BAC1
Effects on the Driver
Potential Effects on Driving Behavior
0.2 percent
  • Relaxes the body
  • Makes the body warm
  • Changes the mood of the person
  • Judgment will be impaired
  • Driver will start losing his visual functions, especially on moving target
  • Driver will find it hard to perform two tasks at the same time
0.5 percent
  • Driver starts to lose muscle function
  • Judgment is impaired
  • Individual will start to feel good
  • Individual exhibits exaggerated behavior
  • Alert level dips
  • Person starts to loosen up
  • Coordinating is now difficult
  • Reduced capability in tracking and moving objects
  • Difficulty in steering
  • Diminished response in attending to emergency situations on the road
0.8 percent
  • Driver starts to feel poor muscle coordination, including poor vision and reaction times
  • Person experiences difficulty detecting danger
  • Self control, judgment, reason and decision making skills are compromised
  • Person experiences short-memory loss
  • Difficulty controlling speed
  • Difficulty concentrating
  • Drivers having problem processing information, like signal detection
  • Perception is hampered
0.10 percent
  • Obvious deterioration of control and reaction time
  • Person starts to suffer from poor coordination, slurred speech and slowed thinking
  • Driver will find it hard to follow lanes, and put on the brakes immediately
0.15 percent
  • Less muscle control now obvious
  • Person may start to vomit, and he now loses balance
  • Driver’s visual and auditory control are now compromised
  • Substantial impairment is observed, and this affects the capacity to responsibly drive the vehicle
1 Information in this table shows the BAC level at which the effect usually is first observed, and has been gathered from a variety of sources including the National Highway Traffic Safety Administration, the National Institute on Alcohol Abuse and Alcoholism, the American Medical Association, the National Commission Against Drunk Driving, and


Question: Can I still stay safe even if I plan to drink and travel?


    Yes you can, provided you allow another person to take the steering wheel. Make sure to do the following:

  • Allow another person to drive the car
  • Ask your host if you can spend the night at the house
  • Take a cab on your way home
  • Wear seat belts if you want to drive home and you chose not to drink. This is your best tool against impaired individuals on the road.

Please Don’t Drink and Drive!


All states have passed a .08 per se law. the final one took effect in august of 2005.

* Calculations are estimates only and not to be relied upon for real life situations. This is because there are so many subtle differences, such as varying metabolic rates, medications being taken, how frequent drinks were taken, and other health issues. Therefore, this calculator should be used for general purpose information only.

Additional BAC details are available from the NHTSA

Disclaimer: This is in no way designed to be a guideline for how much you can legally drink!


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