Finance Health Math Other Blog
Login

Blood Alcohol Calculator

Estimate Your Blood Alcohol Content (BAC)

Estimate your BAC based on the Widmark formula. Note: This is a mathematical estimate and should not be used to determine safety for driving.

How many hours ago did you start drinking?

Your Results

Ready to Calculate

Enter your details and drinks to estimate your blood alcohol content.

What is Blood Alcohol Content (BAC)?

Blood Alcohol Content (BAC) is a measurement of alcohol intoxication used for legal or medical purposes. A BAC of 0.08% means that there are 0.08 grams of alcohol for every 100 mL of blood in your body.

The Widmark Formula

The standard mathematical model used to estimate BAC based on body weight, gender, and alcohol consumed over time.

Metabolism Rate

The human body typically processes alcohol at a constant rate of approximately 0.015% per hour.

Global Legal Driving Limits

Country / Region Standard Limit Professional / Young Drivers
USA, UK, Canada, Singapore 0.08% 0.00% - 0.02%
Australia, Germany, France, Italy 0.05% 0.00% - 0.02%
Norway, Sweden, Poland, China 0.02% 0.00%
Czech Republic, Hungary, UAE 0.00% Zero Tolerance

Limits vary by local jurisdiction. Always check local laws.

Effects of Alcohol by BAC Level

0.02% - 0.05%

Mild relaxation, slight body warmth, altered mood, and minor loss of judgment.

0.06% - 0.10%

Impaired coordination, slowed reaction time, reduced peripheral vision, and poor judgment.

0.15% - 0.30%

Severe impairment, loss of balance, vomiting, slurred speech, and potential blackouts.

Frequently Asked Questions

No. Common myths like drinking coffee, taking a cold shower, or exercising do not lower your BAC. Only time allows your liver to metabolize the alcohol. The average rate is 0.015% per hour.

Eating before or while drinking slows the absorption of alcohol into the bloodstream. This can lead to a lower peak BAC compared to drinking on an empty stomach, but the total amount of alcohol processed remains the same.

No. This calculator uses the Widmark formula, which is a mathematical estimate. Real-world BAC is influenced by hydration, body fat percentage, medications, liver health, and recent food consumption. Never rely on this for legal or safety decisions.
Strict Medical & Legal Disclaimer
This Blood Alcohol Calculator is for informational and educational purposes only. It should NOT be used to determine if it is safe or legal to drive or operate machinery. Many factors including metabolism, medications, food intake, and individual health significantly affect BAC. Never drink and drive. Multicalc assumes no liability for the use or misuse of this information.
Related Health Tools
BMI Calculator
Check your health category
Calorie Deficit
Weight loss planner
BMR Calculator
Resting energy burn
Drinking Safety Tips
  • Alternate every alcoholic drink with a glass of water.
  • Eat a protein-rich meal before you start drinking.
  • Know your limits and never feel pressured to drink.
  • Always have a designated driver or use a ride-share app.
Learn More

Alcohol & Health:

Medical Disclaimer
BAC estimates are for educational purposes only. Individual metabolism varies significantly. Never rely on this calculator to determine your ability to drive.