How big is the sun?

The sun's mass is estimated to be 1.989 times 10E30 kilograms, about the equivalent of 333,000 Earths, and has a diameter of about 864,938 miles. About 99.8 percent of the entire mass of the solar system is contained within the sun.

The sun is a relatively small star in the Milky Way Galaxy. It is classified as a yellow dwarf star, also called a G dwarf star, and it is one of about 10 billion similar stars in the galaxy. Red giant stars, such as Betelgeuse, are much more voluminous.

Astronomers think that in about 5 billion years, the sun will use up all its hydrogen and become a red giant itself. This transformation will destroy all the inner solar system planets, including the Earth.