11 inch on your hand size 11 1/2 for the most depends on hands size for The most time
13"
get one youths hand
11 3/4-12 depending on size of hand. However for a pitcher it should be at least 11.5. Most prefer 12. Make sure glove does not have I or H posts, traps or closed webbing for pitching.
A small size glove
Check here: http://www.baseball-equipment-info.com/baseball-glove-size.html
Robinson Cano uses a size 11.50 glove.
You should get a 7.75x3.15
This depends on the position he plays. If he is a middle infielder (Shortstop or Second Base), you would want to get him a smaller glove to improve transfer of the ball from the glove to his throwing hand - about 9-10 in. If he plays outfield, the his glove should be much bigger to improve catching ability. This is about 11-12 inches. For a first baseman, buy a first baseman's glove (it will say on the tag) that is about 12 inches or longer. Third baseman's gloves should be about 11 inches. A catchers mitt is basically any catcher's mit you can hold up. Pitcher's should be around 10-11 inches with a thick web (pocket). If your player has never played before, he will probably be playing second base or outfield, and for him a large glove is recommended. For the average 13-year-old, a 9-12 inch glove is proper.
It all depends on the kind of glove. First base gloves are much bigger than a fielder's glove. Most fielders use a 12" or 13".
Rawlings Pro 8 is a 12" glove!
Take into account that I'm only guessing, maybe size 9 or 10.