Hold the end of the tape measure at the tip of the longest finger of the player's hand. For most people the longest finger will be the middle finger.
Run the tape measure down along the longest finger and through the palm to where the hand joins the wrist. Lay the tape measure flat so the tape is touching the hand from the top of the finger to the base of the palm.
Select a mitt to match the measurement of the hand. Baseball and softball gloves are sized in inches, from 9 inches for youth to 13 inches for adults.
Try the glove on the hand to check the fit.