How big is the Earth in miles?

The Earth's equatorial circumference is 24,902 miles. Due mainly to the oblate shape of the Earth, its circumference along a line of longitude comes out to be somewhat less: 24,860 miles. Earth has a surface area of 197 million square miles.

Earth has an average radius of 3,959 miles. Due to the centrifugal effect of its rotation, the planet bulges somewhat at its equator. This bulge makes Earth's maximum diameter at the equator 7,926 miles, as opposed to its polar diameter of 7,900 miles. Earth is the fifth largest planet in the solar system; only the four gas giants exceed its size.