Most Accurate Free Blood Alcoholic Calcuator (BAC)

Blood Alcohol Content (BAC) Calculator: How It Works and Why It Matters

The tool considers your weight and how many drinks you have consumed in a given period, so it approximates your Blood Alcohol Concentration. 

Use this calculator to estimate how much alcohol is in your bloodstream and how your blood alcohol content relates to the legal limit for driving in the United States.

What is BAC?

A person’s blood alcohol concentration (BAC) is a popular way to measure how drunk they are.  It is usually given as an amount of alcohol in the blood volume. 

For example, in the United States (US), a BAC of 0.08 (0.08%) would equate to 0.08 grams of alcohol per 100 milliliters.

The legal limit for US drivers’ BAC is 0.08%. Drivers over the legal drinking age in the United States, 21, who have a BAC either equal to or above 0.08% risk fines. 

Penalties for persons under the age of twenty-one are more severe, however state-specific. For people under the age of 21, the legal limit goes from 0.01% to 0.05%. 

What is a BAC Calculator?

A BAC calculator is a tool that estimates your BAC level based on factors such as:

• The number of drinks consumed
• The type and size of the drinks
• Your body weight
• Your gender
• The duration of drinking
• Food intake

These calculators provide an estimate but are not 100% accurate. The best way to determine your exact BAC is to use a breathalyzer or blood test.

How is BAC Calculated?

BAC is calculated using formulas such as the Widmark Formula:

The Widmark Factor varies by gender:

• 0.68 for men
• 0.55 for women

Widmark Formula

%BAC = (A x 5.14 / (W x r)) – .015 x H

Factors That Affect BAC

Number of Drinks: Your BAC will be higher if you drink more booze.

Body Weight: When people drink the same amount of alcohol, heavier people usually have a lower BAC than smaller people.

Gender: Because of changes in body composition, women frequently have a higher BAC than men after drinking the same amount.

Eating: Eating before or while drinking slows down the body’s absorption of alcohol.

Metabolism: Your liver breaks down about 0.015 percent of your blood alcohol every hour, which means that alcohol leaves your body slowly.

Type of Alcohol: Different drinking drinks have different amounts of alcohol in them.

Speed of Drinking: If you drink more quickly, your BAC will rise faster.

Legal BAC Limits in the U.S.

0.08% – Standard legal limit for driving in most states

0.04% – Commercial drivers’ legal limit

0.02% – Zero-tolerance limit for drivers under 21

Drive Limits Regional details of USA

Why Use a BAC Calculator?

• Encourages drinking responsibly by showing you when to stop.
• Legal problems and accidents can be avoided by not getting a DUI.
• Learn how long it takes for booze to leave your body and use that information to estimate your sobriety time.
• Stops drunk people from doing dangerous things.

Limitations of BAC Calculators

BAC tools are helpful, but they only give you an idea.  They don’t take into account:

• Changes in each person’s metabolism
• Prescription drugs or health problems
• Levels of dehydration
• Personal tolerance for alcohol

How to Reduce BAC Levels?

Wait it out: Over time, your body will naturally eliminate the booze.

Drink water: Helps with hydration and processing booze.

Food slows down the absorption of booze.

Get rest: Sleeping doesn’t speed up the metabolism of booze, but it does stop you from drinking more.

Disclaimer

BAC estimations are estimates and should not be used to determine legal or safety intoxication levels. It can’t fully tell you your BAC level or if you’re legally allowed to drive a car because of all the factors that affect it. If you have any alcohol in your body, please don’t drive.  

Health, medications, and diet affect alcohol metabolism and BAC.  Be careful and responsible with drinking.