← Back to Calculator Free · No login · Instant

Blood Alcohol Content (BAC) Calculator

BAC determines your level of intoxication. Knowing your approximate BAC — and how long it takes to metabolize — helps you make smarter decisions about driving and personal safety.

Calculate My BAC Now

BAC by Drinks: Reference Chart (160 lb person)

Standard DrinksApprox BAC (man)Approx BAC (woman)Effect
1 drink0.02%0.03%Mild relaxation
2 drinks0.04%0.06%Lowered inhibitions
3 drinks0.06%0.09%Impaired judgment
4 drinks0.08%0.12%Legal limit / illegal to drive
5+ drinks0.10%+0.15%+Significantly impaired

How Long to Sober Up

The liver metabolizes alcohol at approximately 0.015% BAC per hour — and you cannot speed this up with coffee, food, or water. Those only make you more alert, not less impaired.

To reach 0.00% from 0.08%: 0.08 ÷ 0.015 = 5.3 hours. From 0.15%: 10 hours.

The Legal Limit & Consequences

Frequently Asked Questions

How accurate is a BAC calculator?

BAC calculators provide estimates based on the Widmark formula. Actual BAC varies with food intake, metabolism, hydration, and medications. Use results as guidance only — never as a definitive safety check.

Does food lower your BAC?

Food slows alcohol absorption but does not reduce BAC that is already in your bloodstream. Eating before drinking slows how quickly alcohol enters your system.

Can I drive if my calculated BAC is below 0.08%?

Legal limits do not equal "safe to drive." Impairment begins at 0.02%. If you feel any effects from alcohol, do not drive. Use a rideshare or designate a sober driver.

Ready to calculate?

Free, instant, no login needed.

Calculate My BAC Now