these pants are so cute on my baby and they are true to size, my son is 3 months old and weighs around 17 pounds now and i ordered the 3-6 months and they fit him perfect so i ordered some more in 6-9 months because he is a big baby but these will fit the average size baby perfect in the normal size and the waist is very stretchy so its not too tight and also not falling off of skinny babies and they match up really well with just about every brand of onesies that i own wich is awesome also, i just wish i could find them in the brown that they show on here but they're never available, oh well maybe someday but for now im happy with these and they r very soft and comfy and they have these adorable little pockets on both legs on the sides that are super cute, i would definately recommend these for all babies, chubby and skinny.