Solo Cups- Plant size question

Whats the average size you can get a plant to in solo cups? Reason being is i have 2 autoflower's in solo cups that just showed their first nuts, Im going to seperate these, i just want to make sure i dont need to transplant them.. The plants are still small, maybe like 4 inch's tall with a few sets of leaves..

Bump...............................

if it is a male leave it in the solo cups. but in theory you can get pretty damn big plants in a 18oz cup. go check out the link in my sig for some pictures.