not necessarily on the calved and forearms. I have HUGE forearms and larger than normal calves, that i hardly have to train. BUT, i have huge bone structure and huge joints, both are not something a competing bodybuilder wants as it doesn't look as good on muscle insertion points and generally makes me look less defined.
I think you can look at your parents and get an idea. Look at their build, their bone structure, look at yours. Look at your dads shoulders, look at the width of your shoulders compared to your back/lats. Look at your back, its thickness. Look at other pro's other competitors and try to get a baseline comparison.