An 8-year-old takes about 10.75" at second base or shortstop (10.5–11.25"), 10.75" at third and 11.5" in the outfield. At 8 a player can be in Minor League (46 ft pitching, 60 ft bases). Typical hand: 6–6.5"; median height 4'4".
Two charts at 8
Rawlings lists youth 7–12, infield at 10.25–11.5"; Baseball Monkey’s baseball, ages 8–10 band gives 10.5–11.25". They overlap at 10.5–11.25", and the sizer picks the middle: 10.75".
At 8 a pitcher’s glove (10.75") wants a closed or basket web, a middle infield (2b / ss) glove of 10.75" an I-Web, and a third baseman’s 10.75" an H-web.
The game at 8
In Little League an 8-year-old plays in Minor League (ages 5–12, 46 ft pitching, 60 ft bases). Pitchers are limited to 50 pitches a day at this league age. The next step is Little League (Majors) from 9.
CDC growth charts put the median 8½-year-old boy at 131 cm (4'4") and girl at 130.6 cm (4'3"); the 5th to 95th percentile for boys runs 4'0" to 4'8". A tall player at the age is often a size ahead in the hand too.
Check the hand
Rawlings’ batting-glove chart puts hands at 8 in Youth Small (6–6.25") and Youth Medium (6.25–6.5"), measured from the base of the palm to the tip of the middle finger. Measure it 1:1 in Mode 01 (finger plus palm): a longer hand moves the pick toward 11.25", a shorter one toward 10.5".
For comparison, the 7-year-old sheet starts from 10.5".