Neptune's distance from Earth varies because both planets orbit the Sun at different speeds and distances. On average, Neptune is about 2.8 billion miles (4.5 billion kilometers) away from Earth

. The closest approach, when Earth and Neptune line up on the same side of the Sun (opposition), is about 2.7 billion miles (4.3 billion kilometers)

. When they are on opposite sides of the Sun, the distance can increase to about 2.9 billion miles (4.7 billion kilometers)

. As of early May 2025, the distance from Earth to Neptune is approximately 4.57 billion kilometers (about 30.56 astronomical units), which corresponds to light taking a little over 4 hours to travel from Neptune to Earth

. In summary:

• Average distance: ~2.8 billion miles (4.5 billion km)
• Closest distance (opposition): ~2.7 billion miles (4.3 billion km)
• Farthest distance (conjunction): ~2.9 billion miles (4.7 billion km)
• Current distance (May 2025): ~4.57 billion km (30.56 AU)

This variability is due to the elliptical orbits and relative positions of Earth and Neptune around the Sun