"I ordered this costume in Med. for my Grandson, 9 years old, who normally wears a size 10. The top was entirely too small, but the pants were okay. The material is very thin. I returned the item (returns are very easy & customer service was very curteous). I received the Large and the top fits but the pants are way too big (large enough for a grown man). We were able to alter them to fit. The hat was also very filmsey, without much shape. Was not real pleased with the quality of this custume but I was extremely pleased with the customer service.."