Kids' Gloves Size Chart, US- fox youth glove sizes ,Gloves Size Chart, Kids How to Use The Glove Size Chart? Measure your child's hand width. See the illustration. Hand width is the hand circumference, just over the knuckles. Measure both hands, and use the largest measurements (dominant hand is often larger). Please note that all children have different hands and often also hand sizes.Youth Riding Gear Size Guide | MotoSportYouth Riding Gear Size Chart . Compare the following size chart for Fox Riding Youth Pants with that of Fly Racing Boys Pants: As you can see Fox and Fly don't exactly match up and Fox uses a youth size guide which covers boys and girls while Fly has specific charts for boys and girls.