How Much Bigger Is the Sun Than Earth?

Quick Answer

The Sun's diameter is approximately 1.4 million km, about 109 times the diameter of Earth. If the Sun were scaled down to a large ball with a diameter of 1 m, Earth would become a small marble with a diameter of about 9 mm.

Scaling Down the Sizes

Solar system

While the diameter is 109 times larger, the volume is not simply 109 times greater. Because the volume of a sphere is proportional to the cube of its diameter, simplifying them into perfect spheres means that approximately 1.3 million Earth volumes would fit inside the Sun. Since physical objects cannot be packed without gaps, this figure represents a volume ratio.

If It Is 109 Times Larger, Why Does the Difference Look Smaller on Screen?

The massive Sun Capturing both the Sun and Earth on a single screen makes Earth appear as small as a tiny dot. Educational illustrations often enlarge Earth to keep it visible, or magnify the two bodies separately. Illustrating distance to the same scale presents an even larger challenge: since the distance between the Sun and Earth is about 150 million km, even in a model where the Sun is 1 m wide, Earth would need to be placed about 107 m away.

ScaleCheck's solar system exhibition allows you to navigate and zoom in on each celestial body, but the size values used for ranking maintain true diameter proportions.

Measurement Standards and Margins

The Sun has no solid surface. The diameter provided by NASA is a representative figure based on the photosphere, the luminous surface. Earth's equator also bulges slightly due to rotation, resulting in different equatorial and polar diameters. The values in this article's table are rounded numbers intended for easy comparison, not for precision orbital calculations.