⚠️ Disclaimer: This calculator is for educational purposes only. BAC estimates are approximations. Never use any calculator to decide whether it is safe to drive or operate machinery.
How to Use the BAC Calculator
Enter your gender, body weight, number and type of drinks consumed, and hours spent drinking. The Widmark formula estimates your current blood alcohol level and time until sober.
WHO Recommended Parameters
The WHO notes there is no universally safe limit for alcohol consumption. Calculations provided are standard formula metrics, but always adhere to safe local guidelines and never drive after drinking.
FAQs
How is BAC calculated?
The Widmark formula estimates BAC: BAC = (Alcohol consumed in grams) / (Body weight in grams × distribution factor r) − (elimination rate × hours). The distribution factor r is 0.68 for men and 0.55 for women.
What BAC level is illegal for driving?
In most countries, the legal limit is 0.08% BAC. In many European countries and parts of Australia, it's 0.05%. Some countries have a 0.00% limit for commercial drivers and young/new drivers.
How long does alcohol stay in your system?
The body metabolises alcohol at approximately 0.015–0.020% BAC per hour. You cannot speed up this process with coffee, water, or food. Only time eliminates alcohol from your blood.
Is this calculator medically accurate?
No. This tool provides estimates based on generalised formulas. Actual BAC depends on many individual factors including metabolism, liver health, medications, and more. Never rely on any calculator to decide if it is safe to drive — when in doubt, don't drive.
Key Benefits
- Uses the Widmark formula
- Gender-specific calculations
- Shows time to reach 0.00% BAC
- Color-coded risk level indicator
- 100% private — no data stored
- Free educational tool