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. The Earth's average radius is 3,959 miles.
Because the Earth slightly flattens out at the poles, its shape is an oblate spheroid, meaning that it is similar to a sphere but is not perfectly regular. The circumference of the Earth at the equator is 24,902 miles. Again, that is a bit more than its circumference from pole to pole, which is 24,860 miles.
At 5.52 grams per cubic centimeter, the Earth is the densest planet in the solar system. The Earth has a mass of 6.6 sextillion tons and a total surface area of 197 million square miles.