When the icy planet is closest to the sun, it lies "only" 2.77 billion miles (4.46 billion km). At its farthest, it passes 2.82 billion miles (4.54 billion km) from the star. Although Neptune is the eighth most distant planet, it was not always. The dwarf planet Pluto occasionally dips inside of Neptune's orbit. read more
Astronomers also measure distance in the Solar System using a measuring tool called the “astronomical unit”. 1 astronomical unit, or AU, is the average distance from the Earth to the Sun; that’s about 150 million km. So, Neptune’s average distance from the Sun is 30.1 AU. Its perihelion is 29.8 AU, and it’s aphelion is 30.4 AU. read more
The average distance of Neptune from the Sun is 2,795,084,800 miles or 4,498,252,900 kilometers. Because its orbit is elliptical, its distance from the Sun changes depending on where it is in its orbit. The closest Neptune gets to the Sun is 2,771,087,000 miles or 4,459,630,000 kilometers. read more