Baseball gloves are measured from the heel along the outside of the index finger to the top of the web, and catcher’s mitts by their circumference. Rawlings sizes youth players aged 7 to 12 in one band (infield 10.25–11.5", outfield 11.5–12.25"); Baseball Monkey splits youth into 8–10 and 11–13 and adds catcher’s mitts. The sizer takes the overlap of the two and moves along it with the player’s hand.
Position first, then age
Middle infielders want a small glove and a shallow pocket for a quick transfer: about 11" at 10 and 11.5" at 16. Third base runs a little longer (11.75" at 16), outfielders the longest fielding gloves (12.5") for reach on fly balls, and first basemen use a mitt of 12–13".
Pitchers want a closed or basket web so the batter cannot read the grip; middle infielders an I-web that drops dirt through; third base and outfield an H-web or trapeze for a deeper pocket.
T-ball to Little League to 60/90
Little League Tee Ball covers ages 4 to 7, the Majors 9 to 12 on a 46 ft pitching distance and 60 ft bases, Intermediate 50/70 ages 11 to 13, and Junior and Senior League move to the 90 ft diamond and 60 ft 6 in. A glove has to grow at the same steps: the 11-to-13 band is where most players move from a youth pattern to an adult one.
Rawlings’ T-ball row covers every position from 8.5 to 10 inches; buy at the bottom for a five-year-old who is still learning to close the glove.
Hand length picks the end of the range
Rawlings’ batting-glove chart ties hand length (palm base to middle tip) to age: Youth S 6–6.25" at 6–8, Youth XL 6.75–7" at 10–11, Adult S 7–7.25" at 11–13. Measure the hand 1:1 in Mode 01 and the ball-glove sizer moves its pick toward the top of the range for a long hand, the bottom for a short one.
Brand cuts differ inside a size: when the sizer lands between two sizes, or on the edge of a band, try both.
Why the screen can be trusted
A browser does not know how big its pixels are, so the sizer starts from a table of 114 phones, tablets, laptops and monitors matched to your screen’s size and pixel ratio, an estimate good to about five percent. Laying a coin or a bank card on the glass and matching its outline replaces the estimate with a measurement good to a fraction of a percent, saved for this screen only.
Browser zoom is corrected automatically from the pixel ratio; pinch zoom is flagged, because nothing drawn is true size until it is undone.
pixels per mm = CSS px across the card ÷ 85.60 mm ID-1 card: 85.60 × 53.98 mm (ISO/IEC 7810)