What is the shape of an American football called?

The shape of an American football is called a prolate spheroid. It is a rounded three-dimensional shape stretched along one central axis, giving the ball its familiar pointed oval appearance.

The football is not a perfect sphere because its elongated form helps it travel efficiently when thrown in a spiral. Its pointed ends also make it behave differently from round balls in flight and after bouncing. The exact design varies slightly between professional, college, and high-school footballs.

An NFL football measures roughly 11 to 11¼ inches along its long axis. Its long circumference is about 28 to 28½ inches, while its short circumference is about 21 to 21¼ inches. It weighs between 14 and 15 ounces and is inflated to 12½–13½ pounds per square inch.

“Ellipsoid” is a broader mathematical term that can describe many egg- or oval-shaped solids. A prolate spheroid is the more precise canonical answer because it describes an ellipsoid formed by rotating an ellipse around its longer axis.