What rep rangebuild muscle size

[Boss Man]

Any weights work can increase metabolism 'tis true, by increasing heatrate and the thermogenic environment in vivo, but high weight, low reps, will still be good for muscle building, in a way low weight, high reps won't.

[Musikman124]

So ideally anywhere from 8-12 reps would be perfect for gaining muscle and you don't really need to go higher (rep-wise)?

[Boss Man]

Nope. Low reps, high weight. High reps low weight will do nothing except cut Hypertrophy potential and increase Lactic Acid formation and also make workouts longer.