The strongest beer (18 grad) I drank was in a bar in Delft (Netherlands), and one pint was enough to get properly drunk. Therefore suggesting 2 drinks is not a good advice :)

I would suggest a no drink maximum with co-workers for the OP. Better to stay on the safe side.

@BЈовић choosing your drinks wisely is also a good idea. The high-strength beers tend to be not the default choice, but if you like trying different beers it's easy to pick something stronger than expected

@BЈовић I'm unfamiliar with grad as a measure of alcohol strength, how does it relate to ABV or proof?

@Tristan it's short for degrees, so I would guess it's the same as the ABV, especially since proof is not really used in the Netherlands.

that was my thought, by 18% seems far stronger than anything I'd consider beer, as you'll struggle to get enough sugars in the mash to get so much alcohol without either distilling or fortifying after the fact. I'm wondering if it's degrees Plato of the mash, in which case 18 degrees would be around 7.2% ABV (depending on the final gravity), certainly a pretty strong beer, but much more achievable

@Tristan No idea - it was long time ago. Normal beer is 4,5-5%. This one was 18%. I think the bar is called lupus, and they change beers every week.

This may be true where you live and work, but it is certainly not universal. Being invited out for drinks can be an act of friendliness and acting like it's still work is seen as rude. Not every culture self-censors, some welcome vigourous debate on controversial subjects. In some teams/companies/industries/countries getting drunk and stupid together with your workmates is an expected rite of passage and its nearly unforgivable not to do so. Perhaps you could add your location and culture into your answer.

@IvoMerchiers et al: It's probably not the same as ABV. Doppelbock can get up to around 12% and Eisbock is then concentrated by partially freezing and removing the ice. For comparison Urbock 23° is apparently 9.6% ABV - still strong for a beer of course

... that suggests @Tristan might be right

@ChrisH 9.6% strong for a beer... Sorry, but that is just the upper end of medium strength were I come from. 10% to 14% is pretty normal for a good triple or quadrupel. Above 14% its gets tricky as the alcohol level starts killing the yeast. With hardier special yeast strains specialty craft beers can get up as high as 18 or 19%. Above that you have "fortified beers" where a distilled spirit (often whiskey, wodka or gin) has been added, but those are more cocktails than true beers.

@Tonny plenty of interesting beers can indeed go higher. I mainly mentioned that Urbock because of the degrees in the name and the easily found ABV. But the common beers sold everywhere aren't that strong are they? I haven't been to the Netherlands for decades but recall the same sort of 4 or 5% lager as in neighbouring countries being ubiquitous. Aren't the stronger ones served in smaller measures as well?

@ChrisH Regular beer and lager is typically 4-5%, but special/craft beers go much higher. I'm Dutch but I live in shouting distance of the Belgian border. We have a lot of Belgian beers here and many of those are much stronger than lager. I actually prefer the high ABV beers and almost never drink lager. As for size: Typical serving size glass is either 0.25 or 0.33 L for any beer here. Sometimes 0.5 L for German Hefeweize if they serve it in the appropriate glass. On beer-tasting events you often see small glasses of 0.1 or 0.15, but those are not normal in cafe's, bars or restaurants.

@Tonny not that different here except beers on tap are served by the pint (568ml) or half. The really strong ones tend to be only seen bottled (250ml or similar), and in good pubs you can get interesting beers up to around 6% on tap; I tend to choose the lower ABV, partly because I'm almost always cycling

I'm going to prune the comments here, as we are now discussing beer and alcohol. But yea, I've tried beers with 15+ alcoholic percentage, but I consider those more lie wine (and should be drank as such, slowly). Pruning now