I will throw in a nice small tank top that matches of some sort to make it a full pajamas set! The waistband is a little bit loose and they are loved, but they are so really cute still. I'd say a medium is more accurate for the waist size of this right now. These are Friday the 13th split color #Halloween pajama pants and a size small 4 to 6. But as I notated, the waistband stretched a little and it could fit more of a medium as well.