120,000 kilometres!
Saturn is the sixth planet from the Sun and the second-largest planet in the Solar System. It is about 120,000 kilometers (75,000 miles) wide at its equator, not counting its rings. Saturn is more flattened than any other planet, so its mean diameter, the width of a perfect sphere with the same volume, is smaller: 116,464 kilometers (72,367 miles).
Saturn is a gas giant with no solid surface, so its size is measured to a level in its atmosphere. Astronomers use the height where the pressure is 1 bar, about the same as the air pressure at sea level on Earth.
Measured that way, Saturn is 120,536 kilometers wide at the equator but only 108,728 kilometers (67,560 miles) from pole to pole. The difference, 11,808 kilometers, is almost the width of Earth. The width at the equator is known to within about 10 kilometers.
The rings are much wider than the planet but far thinner. The ring system reaches up to 282,000 kilometers (175,000 miles) from Saturn, yet the main rings are typically only about 10 meters (30 feet) thick.
Like Jupiter, Saturn is made mostly of hydrogen and helium, the same two main ingredients as the Sun. Density is how tightly mass is packed into a space. Saturn has 95 times the mass of Earth but about 760 times the volume, so on average it is only about one-eighth as dense as Earth. It is the only planet whose average density is less than that of water.
Saturn's rings are made of billions of chunks of ice and rock. Most range from grains as fine as dust to chunks as big as a house, and a few are as large as mountains. The rings may be pieces of comets, asteroids or moons that Saturn's gravity tore apart.
The main rings are named A, B and C. A gap 4,700 kilometers (2,920 miles) wide, called the Cassini Division, separates the A and B rings. As of March 2025, astronomers had confirmed 274 moons around Saturn, far more than any other planet has. One of them, Titan, has lakes of liquid methane.