My son was born at 33 weeks. He was 4lb 5oz and 17.5in. We did preemie clothes for a couple weeks and switched to newborn. He was in newborn a lot longer than he was preemie.
Your little guy is pretty long! I would say newborn, but depending on his weight. Congrats on your baby boy!
How many lbs? Because my son was long but I still had to put him in preemie clothes because his body was tiny
Newborn or even some 0-3 cuz hell be so tall