Earth is the largest of the terrestrial planets of the inner solar system, bigger than Mercury, Venus and Mars. Radius, diameter and circumference The radius of Earth at the equator is 3,963 miles (6,378 kilometers), according to NASA's Goddard Space Flight Center. read more
The width of the Earth — its diameter at the equator — is 7,926 miles. Because the Earth is not a perfect sphere, the measurement of the planet from North Pole to South Pole is slightly less: 7,900 miles. read more
The orbital and axial planes are not precisely aligned: Earth's axis is tilted some 23.44 degrees from the perpendicular to the Earth–Sun plane (the ecliptic), and the Earth–Moon plane is tilted up to ±5.1 degrees against the Earth–Sun plane. read more