Son is 7 and already wearing size 5 shoes?

ok my question is .. I have a 7 yr old son. Who is already wearing a size 5 shoe, is there anywhere i can go online that could tell me what to expect height wise for him... he comes from a family of very tall men, and his mom is 6'5"... i am 6' but was told when i was younger that i would be very tall... guess the lifting weights and smokin stunted my growth,