"Runs small. My little man is in 18 months at 2.5 yrs old. I thought this would fit well. He would need something in a 3T to fit. The shirt is too short and the hole to fit your head through is WAY small. I had to cut open the back just to get it on him! And he's in the 10th percentile! Super cute outfit though. For a halloween costume it will do. If you are looking to get this for a fun dress up costume that will be used over and over it will not hold up to much wear."