Baby clothing sizes are so inaccurate, wtf

E

I’m a FTM and just baffled by baby clothes sizes, especially Carters. I just had to switch my 11 week old (still 2 weeks away from being 3 months old) to 6 MONTH clothes!! And he’s little, 36% for height and weight. 3 month clothes were so tight on him! The 6 month outfits are nice and comfy but still fit him well. So weird.