Alcohol & driving (Switzerland): BAC limits, fines & green L

Alcohol & driving (Switzerland): BAC limits, fines & green L

Last updated: 04.02.2026

Find the key blood-alcohol limits for Swiss roads — including the “green L” (probationary licence) and a BAC calculator for rough orientation.

Important: This is not legal advice. Police and authorities decide based on the statutory procedures (breath/blood test) and the circumstances of the individual case.

BAC limits in Switzerland (quick overview)

0.5‰
Standard limit
For most drivers: 0.5‰ (equivalent to 0.25 mg/l breath alcohol).
0.1‰
“Zero-tolerance” group
For learner permits, probationary licence (“green L”), professional passenger transport etc.: 0.1‰ (0.05 mg/l).
ab 0.8‰
“Qualified unfit to drive”
From 0.8‰ (0.40 mg/l) it gets serious: typically a longer licence suspension and criminal consequences.
Situation Blood limit (‰) Breath limit (mg/l)
Most drivers 0.5 0.25
Learner permit / probationary licence (“green L”) / professional passenger transport (and others) 0.1 0.05
Qualified unfit to drive 0.8 0.40

Note: In practice there are tolerances depending on the procedure (breath/blood). The numbers above are the common thresholds.

“Green L” (probationary licence): What happens with alcohol?

  • During the probationary period the de-facto limit is 0.0 — so no alcohol. Even low values can trigger consequences (legal limit: 0.1‰ / 0.05 mg/l).
  • If your licence is suspended (medium or severe offence), the probationary period is usually extended.
  • A second suspension during the probationary period can lead to revocation of the probationary licence (re-issue only after a blocking period; additional assessments may be required).

How does an alcohol check work?

  1. Stop and check by the police.
  2. Initial breath test — if suspicious, an evidentiary test or a blood draw usually follows.
  3. Depending on the result: criminal proceedings (fine) and separate administrative measures (warning/suspension).

Which consequences apply (rough overview, no guarantee)?

Important: The amount of the fine depends heavily on the situation, prior offences, canton and income (for income-based fines). Additional costs apply (proceedings, assessments, course).
  • 0.5–0.79‰: usually a fine, plus a warning or licence suspension depending on the circumstances.
  • from 0.8‰: qualified unfit to drive — typically licence suspension (at least several months) plus criminal consequences.
  • from 1.6‰: a fitness-to-drive assessment (e.g. traffic-medical) may additionally be ordered.

BAC calculator (estimate) — how long until you’re “okay” again?

The calculator uses a simplified Widmark estimate (default elimination rate 0.15‰/h). It’s an orientation only — individual variation can be significant.

BAC calculator

Widmark estimate. Individual factors (food, medication, health, measurement method) can deviate significantly. When in doubt: don’t drive.

Drinks

Estimated current BAC
–‰
(≈ – mg/l Atemalkohol)
Time until below 0.5‰
–
Time until below 0.1‰
–
Calculation basis
Alcohol consumed (estimated): – g · Time since first drink: – h

FAQ

Does 0.0‰ really apply during the probationary period (“green L”)?

In practice yes — no alcohol. The legal limit for this group is 0.1‰ (0.05 mg/l), so even low values can have consequences.

Is one beer enough to reach 0.5‰?

It depends heavily on body weight, sex, drinking duration and individual elimination rate. The calculator below gives a rough orientation — but the safe choice is: don’t drive.

How fast does the body break down alcohol?

A common rule of thumb is roughly 0.10–0.20‰ per hour (often 0.15‰/h). It varies individually — drinking faster or coffee does not help.

What is the difference between a fine and a licence suspension?

The fine/penalty is criminal. The licence suspension is a separate administrative measure issued by the authorities — both can happen at the same time.

What happens at very high values (e.g. from 1.6‰)?

In addition to longer suspensions, a traffic-medical fitness-to-drive assessment can be ordered. The question then becomes whether you are fit to drive a vehicle at all.

Sources (selection)