How Big is the Sun? | Size of the Sun

The sun is the largest and the most massive object in the solar system, but it is just a medium-sized star among the hundreds of billions of stars in the Milky Way galaxy.

This image from the Solar Dynamics Observatory (SDO) shows the sun at 12:45 PM EDT on July 12, 2012 during an X1.4 class flare. The image is captured in the 304 Angstrom wavelength, which is typically colorized in red and shows temperatures in the 50,000 Kelvin range. (Image credit: NASA/SDO/AIA)

Radius, diameter & circumference

The sunis nearly a perfect sphere. Its equatorial diameter and its polar diameter differ by only 6.2 miles (10 km). The mean radius of the sun is 432,450 miles (696,000 kilometers), which makes its diameter about 864,938 miles (1.392 million km). You could line up 109 Earths across the face of the sun. The sun’s circumference is about 2,713,406 miles (4,366,813 km).