We are making Neptune much bigger than actually it is, but it is just almost thrice the size of Earth. Even though it is the smallest of gas giants, it has a mass more than that of Uranus. So, Neptune is much massive than Earth, at least 17 times, so the volume of Neptune will be at least 50 times the volume of Earth. It will take 3 Earths to make a belt around Neptune. And also, there maybe some objects which are larger than Earth, but smaller than Neptune.
Earth is smaller than Neptune but larger than Venus.
Larger
Earth is about 25% smaller than Neptune.Neptune is about 3.88 times larger than the Earth.
Neptune is so much larger than Earth you could fit almost 60 Earths inside of it.
Neptune has a greater mass than Earth does.
Jupiter, Saturn, Uranus and Neptune are much larger than earth. Venus (slightly), Mars (by half) and Mercury are smaller than earth.
Saturn, Uranus and Neptune are smaller than Jupiter but larger than the earth
Neptune is bigger than the Earth, nearly 58 times bigger by volume.
Earth is small compared to Neptune
Saturn, Uranus, and Neptune are all larger than Earth but smaller than Jupiter.
No planet is smaller than Neptune, but larger than Earth in diameter, but Uranus is there in mass. Uranus, even though larger, is less massive than Neptune. Neptune is a giant planet, but not as large as we believe. It is just 3 or 4 times larger than Earth in diameter, but is 16 times massive. Even Uranus is just 13 times. Jupiter and Saturn are much much bigger than all these planets.
The planet with a diameter larger than Mars but smaller than Neptune is Uranus. Uranus has a diameter of approximately 50,724 kilometers, making it larger than Mars (6,779 kilometers) but smaller than Neptune (49,244 kilometers).