Question: what's the diameter of the earth in miles

title: Earth
text: The shape of Earth is approximately oblate spheroidal . Due to rotation , the Earth is flattened at the poles and bulging around the equator . The diameter of the Earth at the equator is 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 12,742 kilometres ( 7,918 mi ) . Local topography deviates from this idealized spheroid , although on a global scale these deviations are small compared to Earth 's radius : The maximum deviation of only 0.17 % is at the Mariana Trench ( 10,911 metres ( 35,797 ft ) below local sea level ) , whereas Mount Everest ( 8,848 metres ( 29,029 ft ) above local sea level ) represents a deviation of 0.14 % . 

Answer: answer: The diameter of the Earth at the equator is 43 kilometres ( 27 mi ) larger than the pole-to-pole diameter.
 The average diameter of the reference spheroid is 12,742 kilometres ( 7,918 mi ).