Blood Alcohol Calculator

Estimate your Blood Alcohol Content (BAC) based on weight, gender, drinks consumed, and time elapsed. Compare against legal limits worldwide.

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Disclaimer: This calculator is for educational and informational purposes only. It provides estimates and should NOT be used to determine fitness to drive or operate machinery. Individual BAC varies based on many factors not captured here. When in doubt, do not drive.

Legal BAC Limits by Region

RegionLegal Limit
USA (most states)0.08%
USA (commercial)0.04%
USA (under 21)0.00 - 0.02%
UK0.08%
Canada0.08%
Australia0.05%
Germany0.05%
Japan0.03%

How to Use the BAC Calculator

  1. Enter your body weight and select the unit (lbs or kg).
  2. Select your biological sex (affects alcohol metabolism rate).
  3. Enter the number and type of drinks consumed.
  4. Enter hours since your first drink.
  5. Click Calculate BAC to see your estimated level.

Understanding BAC

Blood Alcohol Content (BAC) measures the percentage of alcohol in your bloodstream. This calculator uses the Widmark formula, a widely-accepted estimation method. Results are approximate and individual factors like food intake, medications, tolerance, and liver health also play significant roles.

Features

  • Widmark formula for BAC estimation
  • Multiple drink type support
  • Time-based metabolism calculation
  • Estimated time to sobriety
  • International legal limit comparison
  • 100% client-side processing for full privacy

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Disclaimer: This tool is provided as-is for informational and educational purposes only.

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