Here is a list of the planets in order from smallest to largest:

1. Mercury (radius = 2,440 km)

2. Mars (radius = 3,396 km)

3. Venus (radius = 6,052 km)

4. Earth (radius = 6,371 km)

5. Neptune (radius = 24,764 km)

6. Uranus (radius = 25,362 km)

7. Saturn (radius = 60,268 km)

8. Jupiter (radius = 71,492 km)

Pluto, which used to be considered a planet, is actually a dwarf planet. Dwarf planets are objects that are smaller than planets but larger than asteroids. They also do not have enough gravity to clear their orbits of other objects.