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BAC Calculator

Estimate your blood alcohol content based on drinks consumed. For educational purposes only - never drink and drive.

BAC Calculator

Estimate your Blood Alcohol Content based on drinks consumed

lbskg

Formula

Widmark Formula: BAC = (A / (W × r)) - (β × t)

How to Use This Calculator

  1. 1

    Enter your weight

    Input your body weight in pounds or kilograms.

  2. 2

    Select biological sex

    Choose male or female (affects alcohol metabolism rate).

  3. 3

    Enter drinks consumed

    Input the number of standard drinks and type (beer, wine, spirits).

  4. 4

    Enter time elapsed

    Input hours since your first drink.

  5. 5

    View your estimated BAC

    See your estimated BAC, impairment level, and time to sober.

Frequently Asked Questions

What is a standard drink?

A standard drink contains about 0.6 oz of pure alcohol: 12 oz beer (5%), 5 oz wine (12%), or 1.5 oz spirits (40%). Different drinks may vary.

What BAC is legal to drive?

In most US states, the legal limit is 0.08% BAC. However, impairment begins at much lower levels. Some states have lower limits for commercial drivers (0.04%) or zero tolerance for under 21.

How accurate is this calculator?

This provides estimates only. Actual BAC varies based on food intake, medications, metabolism, and other factors. Never rely on a calculator to determine if you're safe to drive.