Blood Alcohol Content (BAC) Calculator

The Blood Alcohol Content (BAC) Calculator estimates the concentration of alcohol in your bloodstream based on what you've drunk — useful for understanding your impairment level before deciding to drive or make other safety calls. Select your gender, enter your body weight, the number of beers, wines, and liquor drinks consumed, and the time since your first drink to get your BAC percentage. Secondary results include your impairment level, legal driving status, total standard drinks consumed, and estimated time until BAC reaches 0%.

Gender *

Results

Blood Alcohol Content (BAC)

--

Impairment Level

--

Legal Driving Status

--

Total Standard Drinks

--

Time Until BAC Reaches 0%

--

More Biology Tools

Frequently Asked Questions

What is Blood Alcohol Content (BAC)?

Blood Alcohol Content (BAC) is a measurement of the amount of alcohol in your blood, expressed as a percentage. For example, a BAC of 0.08% means there are 0.08 grams of alcohol per 100 milliliters of blood.

What is the legal BAC limit for driving?

In the United States, the legal BAC limit for drivers over 21 is 0.08%. For drivers under 21, the limit is much lower, typically ranging from 0.01% to 0.05% depending on the state.

How accurate is this BAC calculator?

This calculator provides estimates based on general formulas and should not be used to determine if you're safe to drive. Many factors like food consumption, medications, and individual metabolism can affect your actual BAC.

Why does gender affect BAC calculations?

Women typically have lower water content in their bodies compared to men, which means alcohol becomes more concentrated in their blood. This biological difference is factored into BAC calculations.

How long does it take for BAC to reach zero?

The body typically metabolizes alcohol at a rate of about 0.015% BAC per hour. However, this rate can vary based on factors like liver function, food consumption, and overall health.

What factors can affect my BAC besides drinks consumed?

Factors include body weight, gender, food consumption, medications, rate of consumption, and individual metabolism. Empty stomach drinking can significantly increase BAC levels.

Can I use this calculator to determine if I'm safe to drive?

No, this calculator is for educational purposes only. The only way to ensure you're safe to drive is to not drink at all before driving. When in doubt, use alternative transportation.

What are the effects of different BAC levels?

At 0.02-0.05% you may feel relaxed, at 0.05-0.08% coordination begins to decline, at 0.08-0.15% significant impairment occurs, and levels above 0.15% can be extremely dangerous and potentially life-threatening.