Height doesn't matter, standing reach does. I'm 5'7 too and my reach is 7'4 which means I need 32 inches to touch the rim and 40 inches to dunk. I know some people out there with ridiculous reach. There was a post about a 5'5 guy with 7'10 reach so he only needs to jump 32 inches to dunk which is very achievable. As for vertical jump ability, so far I can get half of my fingers over an official rim so my vert is currently at 34 inches. I'll measure my vert again soon because I feel like I can reach 35 inches now.
@@manfredidonofrio7501 I forgot his name but if you happen to search for this 5'5 guy with a 7'10 reach dunking, you will be able to see how crazy his reach in each dunk!