Promillerechner

The calculator uses the Widmark formula, a method developed in 1932 by Swedish forensic medic Erik Widmark. It estimates blood alcohol content (BAC) from total alcohol consumed, body weight and a gender-specific reduction factor (≈0.68 for men, ≈0.55 for women). An assumed elimination rate of 0.15 ‰ per hour is subtracted for elapsed time. Individual factors — stomach contents, metabolism, body fat, medication — can shift the actual value by up to 30 % in either direction.

Germany applies a graduated set of BAC thresholds:

• 0.0 ‰ — Mandatory for novice drivers (probationary period) and under 21 — any detectable alcohol is an offence (§ 24c StVG).
• 0.3 ‰ — ‘Relative unfitness’ — if combined with driving errors or an accident, this becomes a criminal offence (§ 316 StGB).
• 0.5 ‰ — Administrative offence (§ 24a StVG): €500 fine, 2 points, 1-month driving ban for the first offence.
• 1.1 ‰ — Absolute unfitness — automatically a criminal offence regardless of driving behaviour. Licence revocation, fine or imprisonment.
• 1.6 ‰ — An MPU is virtually always ordered after this value, even on the first time.

An MPU (medical-psychological assessment) is regularly ordered when one of the following applies: a single offence at 1.6 ‰ or higher, two or more offences at any BAC, or repeat offences within a short period. The assessor classifies the case under one of four hypotheses (A1–A4): A1 (one-off, no dependency), A2 (problematic consumption), A3 (controlled drinking realistic), A4 (abstinence required, dependency suspected).

• ·Allow at least 12 hours after heavy drinking before driving — the 0.15 ‰/hour rule fails at very low values.
• ·Coffee, food or cold showers do not lower BAC. Only time does.
• ·Mixing with energy drinks or carbonated mixers increases absorption rate.
• ·Calculator results are estimates. Police breathalyser and lab BAC remain authoritative.