The planets in the solar system are not all the same sizes.
If you wanted to compare them in terms of every day objects, with the sun being a beach ball you would get the following sizes:
Sun: 1 meter beach ball
Mercury: 3.5mm (size of a ball bearing in a bike)
Venus: 8.7mm (a wild blueberry)
Earth: 9.1mm (a small marble)
Mars: 4.8mm (a cranberry)
Jupiter: 10cm (an orange)
Saturn: 8.4cm not including rings (a tangerine)
Uranus: 3.64 cm (slightly smaller than a ping pong ball)
Neptune: 3.53cm (slightly smaller than a ping pong ball)
Pluto: 1.6mm (a grape seed)