Personal Information
Add Drinks
⚠️ Please enter a valid weight to see your BAC.
⚠️ DO NOT DRINK AND DRIVE. This is an estimate only.
Learn More About BAC
Use the calculator first, then dig into the topics that matter most when interpreting the result.
Understand BAC
Learn what BAC actually measures, what affects it, and why estimates can differ from how you feel.
Open sectionKnow Your Drinks
See what counts as a standard drink for beer, wine, cocktails, and spirits across major regions.
Open sectionCheck Legal Limits
Compare common BAC driving limits and see why being under the legal limit is not the same as being safe.
Open sectionGet Straight Answers
Read practical answers to questions about morning-after BAC, coffee myths, food, and calculator accuracy.
Open sectionBefore You Trust the Number
Absorption is uneven
BAC can keep rising after your last drink, especially if you drank quickly or on an empty stomach.
Feeling fine means very little
People often feel more capable than they actually are. Impairment can persist even when you feel normal.
Real tests beat estimates
Only a breathalyzer or blood test can measure actual BAC. Treat this calculator as educational support, not proof.
How this BAC estimate is calculated
This calculator uses a Widmark-based approximation with alcohol density, body weight, biological sex coefficient, and a fixed elimination estimate of about 0.015% BAC per hour.
Method inputs
Weight, selected sex coefficient, drink alcohol %, volume, and time since drinking are used to estimate current BAC.
Main limitations
Real BAC can differ due to food intake, medication, hydration, absorption timing, individual metabolism, and pour-size accuracy.