My son is inbetween sizes. NB fit him in the waist but they are short. He fits in some NB shirts/onesies too but mostly 0-3. And he's 3 months. He's long but lean.
@ciraclesmiracle, yeah I see it but is kind of confusing cuz in some of them he is 3 months and now he can also fit in 6 months in different brands so when people asks me I don't even know what to say especially now for Christmas I think every body is buying him clothes
He's 5 months and currently wearing 9mo clothes--soon to be wearing 12mo. Carters has a length/weight chart. The clothing sizes are just based upon the average sized baby of that age, so your little one may wear bigger or smaller clothes depending. And that's just fine! Healthy babies come in all sizes!