BAC calculator

BAC Calculator — Estimate Your BAC Instantly

Use our Blood Alcohol Concentration (BAC) Calculator to quickly and accurately estimate your blood alcohol level based on drinks consumed, body weight, gender, and time. This tool is ideal for anyone wanting to understand alcohol metabolism and drink responsibly.

How to Use the Blood Alcohol Concentration (BAC) Calculator

1. Enter your body weight in pounds or kilograms.
2. Select your gender (male/female) to apply the correct alcohol distribution ratio.
3. Enter the number of standard drinks consumed. One standard drink contains ~14 grams of pure alcohol.
4. Specify the time since your first drink in hours.
5. Click Calculate to see your estimated BAC.
6. Use Clear to reset the inputs.

Formulas Used in the Blood Alcohol Concentration (BAC) Calculator

Our calculator uses the Widmark formula, which is widely accepted for estimating blood alcohol content:

• BAC Formula: (Alcohol Consumed in grams ÷ (Body Weight in grams × r)) × 100 − (0.015 × Hours)
• Alcohol Consumed: Number of Drinks × 14 grams (per standard drink)
• r (Alcohol Distribution Ratio): 0.73 for men, 0.66 for women
• Metabolism: 0.015 per hour is subtracted to account for alcohol breakdown over time

Why Use This Blood Alcohol Concentration (BAC) Calculator?

• 💡 Estimate BAC quickly and accurately without manual math.
• 💻 Works entirely in your browser — no software or downloads required.
• 📱 Fully mobile-responsive and easy to use on any device.
• 🍷 Helps you make safer choices about drinking and driving.

Examples

Example 1: 3 drinks, 70 kg male, 2 hours → BAC ≈ 0.045%
Example 2: 5 drinks, 55 kg female, 1 hour → BAC ≈ 0.094%

Important Notes

Remember that BAC estimates are approximate. Individual tolerance, health, food intake, medications, and other factors can affect your actual blood alcohol content. Always avoid driving if you are unsure of your BAC.