What Is the Average Size of a Star?

The Earth's Sun is an average-sized star, with a diameter of approximately 1.4 million kilometers and a mass of about 1.989 x 10^30 kilograms. The Sun has existed for about 5 billion years and has enough fuel to last for another 4.5 billion years, according to Quantrek.

Some stars are much larger than the sun. For example, Rigel is a blue supergiant, located in the constellation Orion, that is about 62 times larger than Earth's Sun. Even larger is the star Betelgeuse, which is a red giant star about 1,000 times the size of the Sun, according to Universe Today. Other stars are much smaller than the Sun, such as Proxima Centauri, which is only about 14 percent of the Sun's size.