BAC Calculator
Estimate your blood alcohol content based on the drinks you've consumed and understand impairment levels.
Important: This calculator provides estimates only. Actual BAC depends on many factors. Never drink and drive. If you feel impaired, do not drive regardless of calculated BAC.
Blood Alcohol Content Calculator
Estimate your BAC based on drinks consumed, body weight, and time elapsed.
How BAC is calculated: This calculator uses the Widmark formula, which estimates BAC based on body weight, gender (affects body water content), alcohol consumed, and time elapsed. Metabolism typically reduces BAC by approximately 0.015% per hour.
Legal limit: In most US states and many countries, 0.08% is the legal limit for driving. However, impairment begins well before this level.
Understanding Blood Alcohol Content
Blood Alcohol Content (BAC) is the percentage of alcohol in your bloodstream. It's the standard measure used to determine legal intoxication and impairment levels. BAC is affected by how much you drink, your body weight, gender, and how quickly you consume alcohol.
BAC Impairment Levels
0.00 - 0.02%
Little to no impairment. Normal behavior and decision-making. Legal to drive.
0.02 - 0.05%
Mild relaxation and lowered inhibitions. Slight impairment of judgment. Generally legal but caution advised.
0.05 - 0.08%
Reduced coordination and reaction time. Impaired judgment. Illegal to drive in some jurisdictions.
0.08%+
Significant impairment. Illegal to drive in most countries. Poor coordination, slurred speech, memory issues.
Factors That Affect BAC
- Body Weight: Heavier individuals typically have a lower BAC after consuming the same amount of alcohol.
- Gender: Women generally have a higher BAC than men after consuming the same amount due to differences in body water content.
- Rate of Consumption: Drinking faster leads to higher peak BAC levels.
- Food Consumption: Drinking on an empty stomach leads to faster absorption and higher BAC.
- Medications: Some medications can intensify the effects of alcohol.
What is a Standard Drink?
A standard drink contains approximately 14 grams (0.6 oz) of pure alcohol. This is equivalent to:
- 12 oz of regular beer (5% alcohol)
- 5 oz of wine (12% alcohol)
- 1.5 oz of distilled spirits (40% alcohol)
Important Safety Information
- Never drink and drive, regardless of your estimated BAC
- Use a designated driver, taxi, or rideshare service
- Individual tolerance varies - you may feel effects at lower BAC levels
- This calculator provides estimates only and should not be used to determine if you're safe to drive
- If you feel impaired at all, do not drive