how big is moon

The Moon is about 3,475 km across, or about 2,159 miles in diameter, which is roughly one-quarter the width of Earth. It’s also the fifth-largest moon in the Solar System and has a mass of about 7.35 × 10^22 kg.

Quick Scoop

• Diameter: 3,475 km (2,159 miles)

• Radius: about 1,737.5 km (1,079.6 miles)

• Surface area: about 38 million square km (14.6 million square miles)

• Mass: about 7.35 × 10^22 kg

• Compared with Earth: about 27% of Earth’s diameter

If you want, I can also give you a simple Earth-vs-Moon size comparison in one line.