Blood Alcohol Calculator
Estimate your blood alcohol content. With gender, weight, drinks and drinking duration. Scientifically based, free, no registration required.
Note: These calculations are for informational purposes only and do not replace professional tax or financial advice. All information without guarantee.
FAQ
Frequently Asked Questions
How is blood alcohol content calculated?
BAC is calculated using the Widmark formula: alcohol in grams divided by (body weight times reduction factor -- 0.7 for men, 0.6 for women). The result is blood alcohol in per mille.
What are the legal alcohol limits for driving in Germany?
The legal limit is 0.5 per mille (0.0 for drivers under 21 or in their probation period). From 0.3 per mille, punishment applies if driving ability is impaired. Above 1.1 per mille is absolute unfitness to drive.
Does this calculator replace a doctor visit?
No. This calculator provides general orientation only. For medical questions, or before starting a diet, therapy or treatment, always consult a qualified physician or therapist.
Guide
Quick Answer
The blood alcohol calculator estimates blood alcohol content after consuming alcoholic drinks and the expected time to sober up.
What is the Blood Alcohol Calculator?
The blood alcohol calculator estimates blood alcohol content after consuming alcoholic drinks and the expected time to sober up.
How does the Blood Alcohol Calculator work?
Enter sex, weight and drinks consumed. The calculator computes blood alcohol using the Widmark formula: BAC = alcohol amount / (body weight * distribution factor). Hourly metabolism (approx. 0.1-0.15 per mille) shows when you will be sober again.
Key Data and Facts
Widmark factor: men 0.68, women 0.55. Alcohol metabolism: approx. 0.1-0.15 per mille/hour. Driving limit: 0.5 per mille (0.0 for new drivers). Absolute unfitness: 1.1 per mille.
Step-by-Step Guide
How to calculate your blood alcohol level step by step: 1. Enter sex and body weight: The Widmark distribution factor is 0.68 for men and 0.55 for women. 2. Enter the drinks: Specify the type, quantity and alcohol content. Pure alcohol (g) = quantity (ml) x alcohol content (vol-%) x 0.8 / 100. Example: 0.5 l of beer (5 %) = 500 x 0.05 x 0.8 = 20 g of alcohol. 3. Calculate the per-mille value: Per mille = alcohol (g) / (body weight x distribution factor). 4. Subtract the resorption deficit: About 10-30 % of the alcohol is not resorbed. The calculator deducts a flat rate of about 15 %. 5. Calculate the breakdown time: The body breaks down about 0.1-0.15 per mille per hour. Sober from = per-mille value / 0.15. 6. Note the limits: 0.0 per mille for novice drivers, 0.5 per mille in general, 1.1 per mille absolute unfitness to drive.
Calculation Example
Man, 80 kg, drinks 2 x 0.5 l beer (5 %): alcohol = 2 x 20 g = 40 g. Per mille = 40 / (80 x 0.68) = 0.74 minus 15 % absorption deficit = approx. 0.63 per mille. Elimination time: approx. 4.2 hours.
Sources · E-E-A-T
Official sources
Calculations are based on applicable German laws and official data:
Full methodology at Methodology.
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