They fit my six year old daughter just fine. Given their adjustable nature they would probably fit kids as young as four, depending on size. The elastic in the straps is strong enough to hold the pads in place, but not so tight as to cut off circulation. My only concern is with the propensity of the Velcro hooks to pull up strings from the straps. In time this will probably cause these pads to become unusable, but careful use and storage should extend their usable life long enough to justify the expense.