How Big Is the Moon?

“How big is the moon? This one is an easy approximation to remember. It’s about 1/4 the size of Earth. Specifically, it’s 27% in diameter.”

The moon is as wide as the United States. From the west to the east coast, the whole United States can fit on the moon.

If you measure the moon’s surface area, it could fit all of Europe, China, the United States, Brazil, and South Africa altogether.

It’s the fifth-largest moon in all of the solar system. And it’s bigger than the dwarf planet Pluto.

READ MORE: How Far Is the Moon?

How does the moon compare to other planets in size?

This table compares the size of the moon in relation to the other planets in our solar system.

First, we compare the difference between radius. Next, we measure the relation between the size of the Earth compared to the moon.

Planet	Radius (km)	Size compared to Earth
Mercury	2,440 km	0.38 of Earth
Venus	6,052 km	0.95 of Earth
Earth	6,371 km	1.00 of Earth
The Moon	1,737 km	0.27 of Earth
Mars	3,390 km	0.53 Earths
Saturn	58,232 km	9.45 Earths
Jupiter	69,911 km	11.21 Earths
Uranus	25,362 km	4.01 Earths
Neptune	24,622 km	3.88 Earths

Size Comparison: The Moon vs Earth vs Mars

In terms of size, the Moon is close to 25% of Earth. On the other hand, Mars is near half (53%) the size of Earth.

The gravity of the moon is 1/6 of Earth which is too weak to hold onto an atmosphere.

If Earth were hollow, you could fit almost 50 moons inside the Earth. If you compare Earth to Mars, it would take 6 Mars to fill in Earth.