The earth is not a perfectly shaped sphere. The equatorial region bulges slightly in comparison to the poles of the planet. This bulge adds about 43 km to the size of the earth at the equator. The average diameter of the earth is 12,742 km. More specifically, the diameter of the planet at the equator is 12,756 km and the longitudinal diameter at the poles is 12,713 km. As you can see that is a difference of 43 km between the two measurements. The bulging effect on earth's equator is a result of the planet spinning on its axis. New scientific studies by NASA and the European Union have added new details to the seemingly simple description of earth's shape.
Shape: Earth is spheroid
Size: Diameter:12,742 km