What is the circumference of the Earth?
The Earth is an oblate ellipsoid, meaning it is a sphere that is slightly flattened at the poles and bulging at the equator. The distance around the Earth at the equator is 24,902 miles (40,075 kilometers). The distance around the Earth through the poles is 24,860 miles (40,008 kilometers). Sources: The New Encyclopaedia Britannica, 15th ed., vol. 4, p. 320; Science and Technology Illustrated, vol. 9., p. 1049.