Neptune is the fourth-largest planet in the Solar System with an equatorial diameter of about 30,775 miles (49,528 kilometers), which is nearly four times wider than Earth
. Its radius is approximately 15,299 miles (24,622 kilometers) on average, with a slightly larger equatorial radius due to its rotation causing an oblate shape
. In terms of volume, Neptune is about 57.7 times the volume of Earth, meaning it could fit roughly 57 Earths inside it
. Its mass is about 17 times that of Earth, making it the third most massive planet in the Solar System despite being smaller than Uranus in size
. Neptune's surface area covers about 2.9 billion square miles (7.6 billion square kilometers)
. It is classified as an ice giant, composed mainly of gases and liquids with no well-defined solid surface
. In summary:
- Diameter: ~30,775 miles (49,528 km)
- Radius: ~15,299 miles (24,622 km)
- Volume: ~57.7 times Earth's volume
- Mass: ~17 times Earth's mass
- Surface area: ~2.9 billion square miles (7.6 billion km²)
This makes Neptune a massive, large planet, but still smaller than the gas giants Jupiter and Saturn
