The Sun is about 1.39–1.4 million kilometers wide , which is roughly 109 times the diameter of Earth and big enough to fit about 1.3 million Earths inside it.

Quick Scoop: How Big Is the Sun?

  • Average diameter: about 1,390,000–1,400,000 km.
  • Radius: about 696,000–700,000 km from center to “surface.”
  • Circumference (going all the way around): about 4.37 million km.
  • Compared to Earth: about 109 times Earth’s diameter, 1.3 million Earths could fit inside its volume.

Think of it this way: if the Sun were a huge hollow ball, you could pour more than a million Earths into it and still have room to spare.

Why “the size of the Sun” is tricky

The Sun is a giant ball of hot plasma, not a solid object with a sharp edge.

Astronomers usually define its “surface” as the photosphere , the bright layer we see in visible light, and that’s what those size numbers are based on.

If you include outer layers like the corona (the Sun’s extended, ghostly atmosphere visible in eclipses), you could say the Sun is “bigger,” but there’s no single hard cutoff where the Sun ends and space begins.

Today’s context and fun perspective

In recent years, educators and science communicators still love using the Sun’s size to blow people’s minds: interactive tools and videos compare the Sun to Earth, airplanes, or walking time around its circumference to make its scale more relatable.

For example, one breakdown notes that the Sun’s radius alone is about twice the distance between Earth and the Moon, so if you replaced Earth with the Sun, the Moon would sit only halfway across the Sun’s diameter.

“You could pour a million Earths into it and still have room left over” is not just a dramatic line – it’s a pretty good everyday summary of the Sun’s scale.

Information gathered from public forums or data available on the internet and portrayed here.