 The shape of Earth approximates an oblate spheroid , a sphere flattened along the axis from pole to pole such that there is a bulge around the equator . This bulge results from the rotation of Earth , and causes the diameter at the equator to be 43 kilometres ( 27 mi ) larger than the pole @-@ to @-@ pole diameter . Thus the point on the surface farthest from Earth 's center of mass is the summit of the equatorial Chimborazo volcano in Ecuador . The average diameter of the reference spheroid is about 12 @,@ 742 kilometres ( 7 @,@ 918 mi ) , which is approximately ( 40 @,@ 000 km ) / π , because the meter was originally defined as 1 / 10 @,@ 000 @,@ 000 of the distance from the equator to the North Pole through Paris , France . 
