At a glance
Have you had a few drinks and need to get behind the wheel? Knowing the legal blood alcohol limit in Belgium is essential for your safety and that of other road users.
In this article, Redion explains everything you need to know: the legal limits depending on your profile, how to calculate your blood alcohol level, the penalties involved and the checks used by the police. Clear information, so you can make the right decisions before driving!
What is the legal blood alcohol limit in Belgium?
The general threshold for drivers
In Belgium, the maximum blood alcohol level allowed for ordinary drivers is set at 0.5 g/l of blood (or 0.22 mg/l of exhaled breath). This threshold corresponds roughly to two standard alcoholic drinks for an average-build adult, although this figure varies according to several individual factors, which we'll detail below.
Specific thresholds for professionals
Professional drivers (lorry, bus and taxi drivers) must comply with a lower blood alcohol limit than the average, around 0.2 g/l of blood (0.09 mg/l of exhaled breath). This near-zero tolerance is due to these professionals' increased responsibility, and the potential risks to their passengers as well as other road users.
Recent changes to the law
Since 1 June 2023, the blood alcohol level that leads to immediate licence suspension has dropped from 0.65 to 0.50 mg/l of exhaled breath (i.e. from 1.5 to 1.2 g/l of blood). More recently still, the province of Flemish Brabant lowered the licence-suspension threshold to 0.35 mg/l from November 2025, a measure that's part of a wider push for stronger road safety.
Understanding units of alcohol and their impact
What is a unit of alcohol?
A unit of alcohol corresponds to around 10 grams of pure alcohol. This standardised measure lets you objectively compare all alcoholic drinks, whatever their form.
Equivalences for each alcoholic drink
Contrary to popular belief, the amount of alcohol is almost identical for each type of glass designed for the corresponding drink. So we find roughly 10 g of alcohol in:
- 1 glass of wine (12 cl at 12°);
- 1 half-pint of beer (25 cl at 5°);
- 1 glass of aperitif (5 cl at 25°);
- 1 glass of whisky (3 cl at 40°);
- 1 glass of digestif (3 cl of cognac, liqueur, etc.).
From 2 standard drinks, you reach on average a level of 0.5 g/l of blood, which is the maximum blood alcohol level allowed for driving in Belgium. And bear in mind that glasses are far from always being filled to a standard measure!
Factors affecting blood alcohol level
Blood alcohol level varies considerably from one person to another. Indeed, several individual characteristics need to be taken into account, such as:
- Weight. A lighter person will more quickly reach a high blood alcohol level, whereas a heavier person will generally feel less pronounced effects;
- Sex. Women generally metabolise alcohol more slowly (a coefficient of 0.6 versus 0.7 for men);
- Food intake. Drinking on an empty stomach makes blood alcohol levels rise faster;
- Health condition. Certain liver conditions can slow down the elimination of alcohol from the blood.
For example, a 20-year-old woman who is 1.60 m tall and weighs 50 kg will reach the legal blood alcohol limit in Belgium much faster than a 20-year-old man who is 1.80 m tall and weighs 75 kg. Even drinking the same amount of alcohol, the effects will be markedly different from one person to another!
How do you calculate your blood alcohol level?
The theoretical calculation formula
To estimate your blood alcohol level, you can use this formula:
Blood alcohol level (g/l) = [Volume (ml) × Alcohol percentage (%) × 0.8] ÷ [Weight (kg) × Diffusion coefficient]
Where:
- 0.8 = density of alcohol;
- Diffusion coefficient = 0.6 for women and 0.7 for men.
Practical example:
A 60 kg woman drinks 2 glasses of 12° wine (2 × 12 cl):
Level = [(2 × 120 × 0.12 × 0.8) ÷ (60 × 0.6)] = 0.64 g/l!
This person is therefore over the legal limit of 0.5 g/l, with just 2 drinks.
Warning: Watch out for the actual size of your glasses! In practice, they're far from always being standard.
Measuring tools
- Standard breathalysers
Commercially available breathalysers let you measure your blood alcohol level more precisely. These devices analyse exhaled breath and give a result in mg/l of exhaled breath.
- Online calculators
Some websites offer blood-alcohol calculation tools based on information you enter on screen. However, be aware: this type of tool can only give a very rough estimate of your condition and is in no way a substitute for a breathalyser or a blood test.
- Smartphone apps
There are connected breathalysers that plug into a smartphone and provide (via a dedicated app) precise readings of blood alcohol level (for example Floome®, Dräger®).
Warning: Blood alcohol level measured via a blood test is expressed in g/l of blood, whereas a breathalyser measures in mg/l of exhaled breath. For a rough equivalence, double the exhaled-breath value: 0.22 mg/l of breath corresponds to roughly 0.5 g/l of blood (the legal threshold).
Absorption and elimination of alcohol in the body
At least half an hour to be absorbed
The maximum absorption level in the body is reached after around half an hour when drinking on an empty stomach. This rises to around an hour when drinking and eating at the same time. So after having a drink, your blood alcohol level will keep rising for 30 minutes to 1 hour. Keep this in mind if you plan to measure it right after drinking: it's better to wait for the peak!
Elimination: several hours needed
Eliminating alcohol takes much longer than absorbing it. Indeed, a healthy person eliminates between 0.10 and 0.15 grams per litre of blood per hour. So allow around 2 hours for a single unit of alcohol to be fully eliminated.
In other words, if you have 4 drinks during an evening out, you'll generally need to wait between 8 and 10 hours after your last drink before getting back behind the wheel with zero alcohol in your blood. That's why so many positive checks happen... the following morning. Before driving, take a breathalyser test to make sure you're not over the legal limit.
How can you eliminate alcohol from your blood?
Some people claim to know "tricks" to eliminate absorbed alcohol faster: drinking lots of water, drinking oil, strong coffee, taking a cold shower, exercising... Unfortunately, these methods don't change the level of alcohol circulating in your body and therefore have no effect on a blood test. At most, they may give you the false impression of being less under the influence, which is even more dangerous.
In practice, 90-95% of alcohol is metabolised by the liver thanks to specific enzymes. This biological process can't be sped up: you have no choice but to let time do its work!
Blood alcohol checks in Belgium
How a roadside check works
During a police check, the driver is asked to blow into a breathalyser, which measures the alcohol level in exhaled breath. The breath test gives one of 3 possible results:
- S (Safe). The level is below 0.22 mg/l of breath: you can drive on;
- A (Alert). The level is between 0.22 and 0.35 mg/l of breath: a second test will be carried out;
- P (Positive). The level is above 0.35 mg/l of breath: a second test will be carried out.
If the result is A or P, you'll need to blow a second time for a breath analysis, which will determine your alcohol level precisely.
Recent change: the waiting period has been scrapped
Since 1 May 2024, drivers no longer have the option of requesting a 15-minute waiting period before the breath test during an alcohol check. This regulation goes hand in hand with the arrival of new-generation breathalysers, which are fast, precise and reliable, and can detect alcohol levels even if the driver had a drink less than 15 minutes earlier.
Your rights during a check
During a blood alcohol test, you can (under certain conditions) ask for a counter-test (a second breath test or a blood test) if you dispute the result. If the evidence of excess alcohol is questionable, you have the option of refusing the immediate penalty (on-the-spot fine) and opting for a court hearing instead. On the other hand, simply refusing the alcohol test without a valid reason is a serious offence, which can lead to immediate licence suspension and a summons to appear in court.
Penalties and fines for drink driving in Belgium
Penalties, according to the blood alcohol level recorded
Penalties vary depending on the blood alcohol level measured during the check.
Possible additional measures
Depending on the case, the judge may also impose:
- Installation of an alcohol interlock device (alcolock) for a period of 1 to 3 years;
- Medical and psychological reintegration tests;
- An awareness course on the dangers of drink driving;
- Confiscation of the vehicle in the most serious cases.
A closer look at blood alcohol limits for driving across Europe
Belgium sits around the European average, with a threshold of 0.5 g/l. Here are a few examples of blood alcohol thresholds across Europe:
- France, the Netherlands and Germany: 0.5 g/l for experienced drivers, but zero tolerance (0.2 g/l) for young drivers;
- United Kingdom: 0.8 g/l (the highest limit in Western Europe);
- Nordic and Eastern European countries: generally very strict regulations with thresholds of 0.2 g/l (or even zero tolerance).
In France, it's recommended (though not compulsory) to keep a breathalyser in the vehicle, a practice that could inspire other European countries.
Practical tips from Redion
Before getting behind the wheel
- Plan ahead: designate a sober driver (a "Bob") before you start drinking;
- Use alternatives: public transport, taxis, ride-hailing services or a designated driver service;
- Wait long enough: remember that it takes on average 2 hours to eliminate each drink;
- Test yourself: keep a breathalyser in your car to check your level.
Redion's assistance
Redion's Bike and Motorbike contracts include help getting home if you're unfit to drive. Feel free to check out our assistance offers so you can travel with complete peace of mind.
During the festive season
During the end-of-year celebrations, associations such as the "Responsible Young Drivers" run campaigns to safely drive home people who have been drinking.
If you're planning to drink alcohol when you go out, always arrange for a "Bob", someone who won't drink during the event and can drive you home afterwards.
The key message: if you're planning to drink, never get behind the wheel. No destination is worth the risk of causing an accident or losing your licence.
Also read:
- Cycling drunk = losing your driving licence?
- The blood alcohol limit tolerated for driving across Europe
FAQ - Your frequently asked questions about blood alcohol levels in Belgium
The maximum blood alcohol level allowed in Belgium is 0.5 g/l of blood (or 0.22 mg/l of exhaled breath) for ordinary drivers. Professional drivers, meanwhile, are subject to a limit of 0.2 g/l of blood.
First published: 09/2015 - Updated: 01/2026
