The age 1-3 was a little on the big side for my one year old but an acceptable niggle given the wear we will get from the jacket. I think it is important to point out that there are two floats in each pocket and the removal of floats gives the extra room for a growing child as well as adjusting buoyancy.
Great confidence booster with arms free for splashing and playing - my son has no complaints with this unlike the various rings and armbands I have tried.