Newborn or even some 0-3 cuz hell be so tall
How many lbs? Because my son was long but I still had to put him in preemie clothes because his body was tiny
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!