Though the outfield may vary in size from one baseball field to the next, high school, college and major league games are all played with the same infield dimensions, which includes the baseball diamond, pitcher’s mound, home plate and the three bases. Little league players utilize a smaller infield, which helps them to learn the fundamentals of the game, but the three bases are the same size as those used by adults.
The Three Bases
The three bases are first, second and third base. All bases are the same size and all are shaped in a square, with each side being 15 inches long and 3 to 5 inches thick. Each base is made of a canvas-like material that is stuffed with a soft material. The official rules of Major League Baseball state that the bases must be secured to the ground.
The fourth base is home plate, which is a five-sided piece of white rubber. Home plate starts as a square and has two corners removed; the longest side of home plate is 17 inches long, the two shorter straight sides are 8.5 inches long and the two slanted sides are 12 inches in length.