Health

Blood alcohol calculator

The calculator uses a simplified Widmark calculation. The result is only a rough guide and never a basis for driving.

Updated on Apr 21, 2026 Calculator, calculation path and examples on one page

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Calculator

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Calculation path

Step by step

  1. Pure alcohol

    Result: 40.0g

    Beer, wine and shots are calculated with fixed standard quantities.

  2. Maximum theoretical per mille

    Formula: Alcohol in g / (body weight × distribution factor)

    Values inserted: 40.0 / (80.0 × 0.68)

    Result: 0.74‰

  3. Take degradation into account

    Formula: Maximum value - 0.15 ‰ per hour

    Values inserted: 0.74 - 0.45

    Result: 0.29‰

Instructions

How to use this calculator correctly

Input

  • Select gender and weight and enter the number of standard drinks.

Read the result

  • The calculator shows a theoretical peak value and a rough estimate over time.

Important NOTE

  • The computer must never be used as a basis for decision-making for journeys or safety-relevant situations.

Related guide: Correctly classify BMI, calorie requirement and calorie deficit

Examples

Typical calculations

80 kg, two beers, 3 hours.

Two beers

Estimated current per mille: 0.29‰

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65 kg, two glasses of wine, 4 hours.

Wine evening

Estimated current per mille: 0.47 ‰

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75 kg, beer and shots.

Mixed evening

Estimated current per mille: 0.85 ‰

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FAQ

Frequently asked questions

How accurate is the calculator?

Just roughly. Speed ​​of intake, food, gender, body type and state of health significantly change the actual value.

Why does the calculator show a peak value and a current value?

This way you can see what would theoretically be possible immediately after drinking and how time affects it.

Is alcohol reduction really always 0.15 per mille per hour?

No. This is just a common guideline for rough calculations.

Can I rely on the value to drive?

No. The computer is expressly not intended for this.

Why does the calculator use standard drinks?

So that the calculation remains simple and usable for typical everyday situations.

Related calculators

Continue seamlessly

BMI calculator

Calculate BMI from weight and height and classify carefully.

Sources and notes

Rule status and context

Method
Simplified Widmark formula with a flat mining value of 0.15‰ per hour.