An 80 kg man who goes on evening tours and a 55 kg woman who drinks the same amount will not show the same blood alcohol level at all. Talking about a fixed number of glasses to reach 2 grams of alcohol per liter of blood makes no sense without first addressing the variables that can double this figure.
Widmark Formula: the calculation behind each alcoholic drink
Before counting the glasses, we need to understand how the body processes alcohol. The Widmark formula remains the reference for estimating blood alcohol content. It is based on three data points: the mass of pure alcohol consumed (in grams), body weight, and a diffusion coefficient that varies by sex.
This coefficient is about 0.68 for men and 0.55 for women. The higher fat mass, on average in women, absorbs less alcohol than body water, which concentrates ethanol more in the blood.
A standard drink served in a bar (25 cl of beer at 5°, 12.5 cl of wine at 12°, 3 cl of spirits at 40°) contains about 10 g of pure alcohol. It quickly becomes clear why the question about the amount needed to reach 2 grams of alcohol in the blood cannot be solved with a simple multiplication.
How many glasses for 2 g/L according to weight and sex
Let’s apply the formula with concrete profiles. For an 80 kg man, each standard drink raises the blood alcohol level by about 0.20 to 0.25 g/L. Therefore, reaching 2 g/L theoretically requires between 8 and 10 drinks consumed quickly, without elimination.
For a 60 kg woman, the increase per drink is around 0.30 g/L. Six to seven drinks are enough to exceed 2 g/L, still in a scenario of rapid consumption on an empty stomach.
These estimates do not take into account the elimination by the liver, which begins with the first drink. The body eliminates on average between 0.10 and 0.15 g/L per hour. If consumption is spread over several hours, more drinks will be needed to reach this threshold.
Indicative table: estimated blood alcohol content without elimination
| Profile | Estimated increase per drink | Drinks to approach 2 g/L |
|---|---|---|
| Man 80 kg | 0.20 to 0.25 g/L | 8 to 10 |
| Man 65 kg | 0.25 to 0.30 g/L | 7 to 8 |
| Woman 60 kg | 0.28 to 0.33 g/L | 6 to 7 |
| Woman 50 kg | 0.33 to 0.40 g/L | 5 to 6 |
Feedback on this point varies depending on fatigue, stress, or smoking, which alter the speed of absorption and elimination.
Factors that accelerate the rise in blood alcohol level
Drinking on an empty stomach radically changes the situation. Without food in the stomach, alcohol enters the bloodstream much faster. The peak blood alcohol level can be reached in about thirty minutes, compared to over an hour after a meal.
The speed of consumption is the most underestimated factor. Consuming five drinks in one hour results in a much higher blood alcohol level than the same five drinks consumed over three hours, simply because the liver does not have time to eliminate between each drink.
Here are the main parameters that affect blood alcohol levels:
- Body weight: the lighter you are, the higher the concentration of alcohol in the blood for the same amount consumed
- Sex: the lower diffusion coefficient in women leads to a higher blood alcohol level for equal consumption
- Diet: a full stomach slows the absorption of ethanol, while an empty stomach speeds it up
- Liver health: impaired liver function reduces elimination capacity, sometimes dropping below 0.10 g/L per hour
2 g/L of alcohol in the blood: what it means for the body and the law
At 2 grams per liter, we are no longer in the gray area. Reflexes are significantly impaired, the field of vision narrows, and motor coordination is severely disrupted. The liver’s maximum capacity to eliminate alcohol is exceeded well before this threshold, around 2.4 g/L according to medical sources cited by professionals in the restaurant industry.
Beyond 3 g/L, the risk of ethyl coma becomes real. At 5 g/L, life-threatening conditions arise.
Legal thresholds and penalties in France
The legal limit for driving is set at 0.5 g/L (0.2 g/L for probationary licenses). Beyond 0.8 g/L, it falls into the realm of offense, with penalties of up to 2 years in prison and a fine of 4,500 euros. At 2 g/L, one is therefore well within the criminal zone.
Since late 2024, several prefectures have implemented systematic judicialization starting at 0.8 g/L: any driver tested at this level or above is presented to the prosecutor, even without an accident. With a blood alcohol level of 2 g/L, license suspension and vehicle impoundment are almost automatic.
Elimination time after high blood alcohol levels
The liver eliminates alcohol at a relatively constant rate, between 0.10 and 0.15 g/L per hour. No coffee, cold shower, or physical exercise speeds up this process.
To drop from 2 g/L to 0.5 g/L, it takes at least ten hours, often more. Getting back behind the wheel the next morning after an evening at 2 g/L remains dangerous if one has not slept long enough.
A personal breathalyzer remains the only reliable way to check one’s level before driving. Subjective feelings (feeling sober, having eaten, drinking water) do not reflect the actual blood alcohol level.
Remembering a precise number of drinks has its limits. The calculation always depends on individual profiles, speed of consumption, and diet. What does not vary, however, is the risk: at 2 g/L, the body operates in degraded mode, and the law considers the situation a serious offense, with or without an accident.