BAC Calculator

About BAC Calculator

BAC Calculator estimates your Blood Alcohol Content using the well-known Widmark formula — quickly, clearly, and completely offline. Enter how many standard drinks you have had, your body weight, your sex and how long you have been drinking, and the app shows an estimated BAC percent, an impairment category, whether you are over the common 0.08 legal driving limit, and roughly how long until your BAC returns to zero.

WHAT YOU CAN DO
- Set the number of standard drinks with a simple stepper
- Enter body weight in pounds or kilograms
- Choose male or female (different body-water constants)
- Enter hours since your first drink
- See an estimated BAC with a color-coded impairment badge
- See at a glance if the estimate is over the 0.08 limit and the hours until sober

WHAT COUNTS AS A STANDARD DRINK
A built-in reference shows that a standard drink is about 0.6 oz of pure alcohol — roughly a 12 oz beer at 5%, a 5 oz glass of wine at 12%, or a 1.5 oz shot of spirits at 40%. Larger or stronger pours count as more than one drink.

LEARN AS YOU GO
A plain-language Learn tab explains what BAC is, how the Widmark estimate works, and — most importantly — why it is only a rough guide.

IMPORTANT: ESTIMATE ONLY
This app provides a rough estimate for general and educational use only. It is NOT a breathalyzer and must never be used to decide whether it is safe or legal to drive. Real blood alcohol content depends on many factors this formula cannot capture — food, hydration, medication, health conditions, drink strength, metabolism and time. The only truly safe amount of alcohol before driving is none.

NEVER DRINK AND DRIVE. This app is not legal advice and not medical advice. If you have been drinking, do not drive — arrange a taxi, rideshare, or a sober driver, and when in doubt wait it out.

PRIVACY
The app collects no personal data and works fully offline — your inputs never leave your device. Ads are served by Google AdMob, which may use an advertising identifier as described in Google's policies.

Light and dark themes, a tiny download, and no clutter. Use BAC Calculator to understand alcohol's effects — and always plan a safe, sober ride.