i dont think anyone can answer this and be 100% correct. sure there are the smokables like dmt, but for the rest i think the duration is rather variable, as each brain is different. sure, some are longer than others, but for a few friends of mine 2ce lasts 5h while for me it is a 10h experience at the same dose/level. it goes on and on, with lsd and mushrooms also lasting up to 50% longer for some than for others.
the erowid vaults have good suggestions, but it is wise to consider them as just guidelines and explore each substace carefully yourself, seeing how you react to it.
another example would be 4-ho-dipt, which some say should be quite a fast onset (<1h), short trip(<2h), but for me it the comeup was after 2h and the trip lasted around 3 (almost 4) hours.
i guess some are just more sensitive than others. just be careful and like a previous poster said, dont plan on driving afterwards either way