My son is 5 months old and about 14 lbs. This costume was just a LITTLE too big, but it worked just fine for the day. Everyone LOVED our "Popeye family" costumes!
My only complaints about this costume are that the brim on the hat his a LOT longer than it looks in the picture, my baby's eyes were totally covered unless we had the hat sitting high on his head. The other complaint is that there are no leg holes, so, in order to strap my son in his car seat, I had to cut two slits in the back to pull his legs through. Once we took him out of the car we just tucked his legs back in the holes and carried him around. I would still recommend this costume for parents who want to be Popeye, Olive Oyl, and Sweet Pea!