Baseball & Softball
Ball Sports · 9 specs
Direct Answer
Official baseballs are regulated by Major League Baseball (MLB), measuring 9.0–9.25 in (22.9–23.5 cm) in circumference and weighing 5.0–5.25 oz (141.7–148.8 g) with 108 double hand-stitches. Regulation softballs are larger: 12-inch Fastpitch softballs measure 11.875–12.125 in (6.25–7.0 oz), 11-inch Slowpitch softballs measure 10.875–11.125 in (5.875–6.125 oz), and 16-inch Chicago Clincher softballs measure 15.75–16.25 in.
Source: MLB Official Baseball Rules Rule 3.01 / USA Softball Official Rulebook / WBSC Standards · Last reviewed Aug 28, 2026
Specs
| MLB Baseball Circumference | 22.9–23.5 cm (9.0–9.25 in) |
| MLB Baseball Weight | 141.7–148.8 g (5.0–5.25 oz) |
| MLB Baseball Diameter | 7.3–7.5 cm (2.86–2.94 in) |
| Baseball Stitching | 108 Double Stitches in Red Waxed Cotton/Polyester Thread Hand-sewn |
| Baseball Core Construction | Cushioned Cork Sphere wrapped in 3 Layers of Wool/Poly Yarn Standard |
| 12-Inch Fastpitch Softball Circumference | 30.2–30.8 cm (11.875–12.125 in) |
| 12-Inch Fastpitch Softball Weight | 177.2–198.4 g (6.25–7.0 oz) |
| 11-Inch Slowpitch Softball Circumference | 27.6–28.3 cm (10.875–11.125 in) |
| Softball Core Material | Polyurethane Core or Kapok Fiber Core with Optic Yellow Leather COR 0.44–0.47 |
Internal Core Architecture & Seam Aerodynamics
- Multi-Layered Baseball Core: MLB baseballs (manufactured by Rawlings in Costa Rica) feature a cushioned cork center (black rubber enclosing red rubber-cork), tightly wound with 121 yards of 4-ply blue-gray wool yarn, 45 yards of 3-ply white wool yarn, 53 yards of 3-ply blue-gray wool, and 150 yards of fine white poly-cotton finishing yarn.
- 108 Red Stitches: Two dumbbell-shaped pieces of full-grain white alum-tanned cowhide are hand-stitched with exactly 108 double raised seams (88 inches of waxed red thread), generating the boundary-layer aerodynamic turbulence required for curveballs, sliders, and splitters.