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BAC Calculator

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Oftentimes people underestimate just how intoxicated they actually are. While this is not intended as a true measurement tool, this is what the math says your intoxication level is. If you have had any amount of alcohol, do not drive.

Calculating Blood Alcohol Concentration (BAC)

Most of us who casually drink in a social setting have reached the point of realizing when we’ve had one drink too many to make that drive home. 

The truth is, it doesn’t take much alcohol to impair judgment and motor functions. Blood alcohol concentration (BAC) is a scale used to determine how much alcohol a person has consumed. There are many factors that can affect how much alcohol actually enters the bloodstream.

It’s important to understand how BAC is calculated to help better understand the consequences of drinking.

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How Is BAC Calculated?

BAC is measured in milligrams (mg) of alcohol per 100 milliliters (ml) of blood. While a standard drink is, as defined by the Centers for Disease Control and Prevention (CDC), “equal to 14.0 grams (0.6 ounces) of pure alcohol,” this amount of alcohol affects each person differently. 

Measuring 0.6 ounces of alcohol is easier with typical drinks consumed in the United States. You’ll find 0.6 ounces of alcohol (or close to it) in:

  • 12 ounces of beer (5% alcohol content)
  • 8 ounces of malt liquor (7% alcohol content)
  • 5 ounces of wine (12% alcohol content)
  • 1.5 ounces or a “shot” of 80-proof (40% alcohol content) distilled spirits or liquor (e.g., gin, rum, vodka, whiskey)

As for what these standard drinks do to you, there are a lot of moving factors.

Factors Affecting Blood Alcohol Concentration

There are several variables, or factors, that can affect your BAC level.

Biologically, your gender will play a large role in how high your BAC gets from one drink. If you line up three drinks, with the same amount of alcohol content, in front of both a man and a woman, the female will likely have a higher BAC than the male after consuming the same drinks. 

The Harvard Medical School explained this by stating “(female) bodies contain proportionately less water and more fat than men’s bodies. Water dilutes alcohol and fat retains it, so female organs are exposed to higher concentrations of alcohol for longer periods of time.”

Weight and age, as you might expect, play a large role as well. As you age, alcohol takes a bigger toll on your body. Even with increased tolerance, your BAC will slowly climb per drink with age. 

If a person weighs more, they retain more water. Similar to the reason a female has a higher BAC, water dilutes the alcohol in a person that weighs more than another. This lowers a person’s BAC. 

The contents of your stomach also can affect your BAC. If you have a full stomach, your BAC will climb slower than that of someone drinking on an empty stomach. 

If someone is binge drinking, or drinking a lot within a short period of time, they will have a quicker-climbing BAC than someone who is drinking slowly throughout the night. Always remember, time offsets alcohol.

What Are the Effects of an Increased BAC?

So, what does each level of BAC feel like? The thought has crossed the minds of most of us: What does 0.08% actually mean? How do I know when I’ve had too much?

To the best of our ability, here is an overview of what each person typically feels (or doesn’t feel) at each level of alcohol concentration.

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Vertava Health exists to build a happier and healthier future for you and your family. If you have more questions about BAC, or think you or a loved one could benefit from hearing about treatment options for alcohol use disorder, give us a call today at 844-470-0410. We have alcohol rehab at multiple locations across the country and are ready and willing to help you where you are.

BAC Effects
0.02% to 0.07%: At this level, you’ve probably had just a couple of drinks. You likely feel slightly relaxed. You may feel slight lightheadedness and exhibit exaggerated behaviors.
0.08%: This is the legal level of intoxication in all states. When you have reached this level of BAC, you are beginning to have impaired motor skills and balance issues. This is also the point where psychological effects take a stronghold. Most feel more confident in their ability to perform functions (i.e., driving) than is actually possible.
0.09% to 0.13%: Coordination and balance are severely affected when you have a BAC in this range. You likely begin to have blurred vision on top of the coordination issues.
0.14% to 0.19%: The good feelings provided by alcohol reach a boiling point here. Blackouts can begin happening, and walking, talking, and standing become difficult to accomplish.
0.20% to 0.25%: Have you ever seen someone so drunk they needed to be carried? They were at least at this level of BAC. There is a nearly complete sense of numbness to the point that injuries would not be felt.
0.26% to 0.35%: Your life is in danger. You have almost certainly passed out and are in danger of vomiting without regaining consciousness. You may stop breathing at this point.
0.40% and above: In all likelihood, you are comatose at this point.

Blood Alcohol Content FAQs

How do you estimate BAC?

BAC is measured in milligrams (mg) of alcohol per 100 milliliters (ml) of blood. So, it’s easy to understand that it’s no easy thing to estimate. A fairly universal understanding of BAC is that each standard drink equals at least 0.02% in BAC.

This is not always accurate as there are a lot of variables at play. If you ever have the thought you might be close to 0.08% at all, do not drive.

How many drinks is a 0.08% BAC?

Depending on a number of factors, a person will typically reach 0.08% BAC by consuming two to five drinks within a short period of time.

Again, the number one factor in BAC is time. The quicker you consume alcohol, the faster your BAC goes up. The longer you wait after your last drink, the more your BAC will decrease.


Our Blood Alcohol Concentration (BAC) calculator is meant to be used for educational purposes only. It does not serve, nor is it intended to serve, as medical advice or legal advice. We ask that you please consult a healthcare or legal professional above the calculator. 

No BAC calculator is 100% accurate because of many factors that go into determining any given person’s BAC. These factors include weight, age, gender, contents of the stomach, amount of alcohol consumed, and speed at which the alcohol was consumed. BAC may also be affected by a person’s rate of metabolism, medications, and prior health issues. 

The best to expect of the BAC calculator is a rough estimation of BAC based on inputted answers. 

End of story:  If you have been drinking, do not drive.