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BAC Calculator

Estimate blood alcohol content based on drinks consumed, weight, and time elapsed, for educational purposes only and never as a basis for driving.

This is a rough educational estimate only. Actual BAC varies significantly by individual and cannot be measured accurately without a breathalyzer or blood test. Never use this to decide whether it's safe to drive, and never drive after drinking, regardless of the result shown here.
0.038%
Estimated BAC

A standard drink is roughly 12 oz of regular beer, 5 oz of wine, or 1.5 oz of distilled spirits. This estimate uses the widely cited Widmark formula, which does not account for food intake, medication, metabolism, or many other real factors that affect actual blood alcohol content.

About the BAC Calculator

A BAC calculator gives a rough educational estimate of blood alcohol content based on drinks consumed, body weight, sex, and time elapsed, using the widely cited Widmark formula.

How to use

1

Enter the number of standard drinks consumed, your body weight, and your sex.

2

Enter how many hours have passed since your first drink.

3

View the estimated BAC percentage.

Frequently asked questions

How accurate is this estimate?
It's a rough approximation only. Actual BAC is affected by many factors this formula doesn't account for, including food intake, metabolism, medication, and individual physiology, and can only be measured accurately with a breathalyzer or blood test.
Can I use this to decide if I'm okay to drive?
No. This tool is for educational purposes only and should never be used to judge whether it's safe to drive. The only safe choice after drinking is not to drive.

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