BAC Calculator

The most accurate BAC calculator on the Internet(see guide)
Age (18+)
Weight: 65-350 lbs
Height: 40-100 in
Alcohol: 0.5% - 96%
Volume: 1 - 330 oz
Tip: You can enter a few portions of the same drink in one field “Drink”. Just add up the volume of all drinks together and enter the total volume.

2 x standart cans (12 oz) = 24 oz;
2 x "Tall Boy" cans (16 oz) = 32 oz;
2 x "Crowler" cans (32 oz) = 64 oz;
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How to use BAC Calculator

BAC Calculator (blood alcohol content calculator) is designed to help you know:

  • how long you should wait before driving after consuming alcohol;
  • how much alcohol is in your body;
  • how much alcohol is in your blood and in the air you exhale;
  • your degree of intoxication;
  • what consequences there may be and how to handle them;

For the calculator to work correctly, you must follow these instructions:

  1. Specify your gender and age. Your gender affects how much alcohol your body absorbs, while your age determines how fast alcohol is eliminated from your body.
  2. Enter your height and weight. This information is also essential to determine how much alcohol your body absorbs.
  3. Specify the strength and volume of drinks consumed (up to 5 beverages). You can enter strengths of 0.5 to 96% and volumes of 50 to 10,000 ml. If you consumed over 10,000 ml of one beverage, insert the remaining volume in the next field.
  4. Specify whether you drank on a full or empty stomach and tap Calculate.

Our alcohol calculator is perfectly suited for use by drivers in 2019.

BAC Calculator results

Alcohol elimination time is calculated on the basis of your personal characteristics. This value is used to determine when you will be able to drive. The minimum, average, and maximum times are general calculations without regard for particular parameters. In most cases, these parameters can be ignored. 

BAC calculator


  • if you have a severe injury or disease, you should consider the maximum elimination time;
  • if you were highly physically active during the elimination time, consider the minimum time +15-25%;
  • people who drink regularly have a shorter elimination time than those who rarely drink. However, unfortunately, you can't determine your exact elimination time without individual medical tests.

The formula used to measure BAC

The mathematical model used in our BAC Calculator is based on the generally accepted formula of Swedish chemist Erik M.P. Widmark. This formula is used by medical assessors around the world to measure blood alcohol content at a specific time:

BAC calculator formula

where: BAC is blood alcohol content (g/l); t is the time that passed since consumption; A is the mass of pure ethanol in a drink (g); r is the Widmark factor; W is body weight (kg); k is the rate of alcohol consumption (h-1); and b is the alcohol elimination rate ((g/l)/h).

The coefficients are calculated based on the research of S. Seidl (University of Vienna) and Alexander Robert W. Forrest (University of Sheffield).

BAC calculation scheme

Why is our BAC Calculator the most accurate one?

We designed our BAC Calculator by studying and taking into account all the factors and methods used in global forensic medicine. We first rolled out our calculator in 2010, and it has long been available to a limited number of persons in the form of a special Java-based program. During this time, the accuracy of its calculations has been repeatedly confirmed in practice. 

Compared to other online alcohol testers

There are numerous BAC calculators and online alcohol testers available on the internet, but most of them use only the simplest formulas and average (simplified) coefficients. We know of only two other real, full-fledged BAC calculators, but even they take fewer factors into account than our calculator. 

When you can drive after drinking alcohol

You should remember that zero blood alcohol content alone does not give you the right to drive. 

Before driving, make sure you are feeling well and reacting normally, and you can be concentrated. Remember, if you get into a car accident because you aren’t  feeling well, you will be found guilty.

That is why you should never drive when you're hungover, even if the alcohol has been completely eliminated from your body.

Stages of alcohol intoxication

0.03% or less − no effect of alcohol

No effects and normal behavior. The presence of alcohol in your blood can only be confirmed using special tests.

There are no consequences for your body.

0.03-0.05% − insignificant effect of alcohol

Concentration is more difficult, and the following effects may be noticed: talkativeness, a feeling of joy, relaxation, slight euphoria.

There are either no consequences or a slight hangover; no treatment is required.

0.05-0.15% − slight intoxication

Sensations are blunted, disinhibition and extroversion may be experienced. Reasoning, comprehension, and peripheral vision may be impaired.

There may be a slight hangover, and symptoms can be alleviated by any pain reliever.

0.15-0.25% − moderate intoxication

Mood swings, excessive expressiveness, strong anger or sadness, violent behavior, and decreased libido may be experienced. Reflexes and key motor skills are impaired, and reactions are slowed. There is a risk of temporary alcohol poisoning.

Moderate or severe hangover. Recommendations: take a pain reliever and drink a lot of mineral water. If you don't have mineral water, drink regular water.

0.25-0.3% − severe intoxication

Behavioral changes including stupor, blunted sensations, and loss of comprehension are common. There is the risk of falling unconscious. You may also experience severe mobility disturbances or loss of memory.

Severe hangover. Recommendations: take a pain reliever and drink a lot of mineral water. If you don't have mineral water, drink regular water. Make yourself drink water even if you don't want to.

0.3-0.5% − severe alcohol poisoning, risk of death

Severe inhibition of central nervous functions, loss of consciousness, risk of coma or even death. You may experience uncontrolled urination, impaired breathing, and complete loss of balance.

Recommendations: take a pain reliever and drink a lot of mineral water. If you don't have mineral water, drink ordinary water. Make yourself drink water even if you don't want to. You should also seek medical aid.

0.5% or more − lethal poisoning

You are at high risk of an alcohol-induced coma, loss of consciousness, and even death.

Seek medical attention immediately!

How alcohol is measured in court

During their assessments, medical assessors use the same formulas and guidelines we used to develop our BAC Calculator. However, in the context of a court case, medical assessors use the coefficients that are most beneficial for the defendant. In cases when a traffic accident took place several hours before blood was taken from the accused, the minimum alcohol elimination rate used is 0.01%/hour. But if it is to be demonstrated that at the time of the accident the accused was not responsible for their actions, the maximum rate is 0.02%/hour. Unfortunately, medical assessors don't always use accurate formulas and often select the average values of coefficients included in the regulations.

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