Here is a table if you wanted to make a scale version of the solar system. It’s based on making the Earth a 1in sphere and then gives how far from the Sun each planet should be and how big of a ball to use for each planet.

This is from frink a programming language based on accurate representation of units. If you are into really nerding-out take a look at the unit data which describes lots of possible unit conversions.

Name Distance from Sun Diameter
Sun 9 feet, 1.3 in
Mercury 378 feet, 8.8 in 0.383 in
Venus 707 feet, 7.6 in 0.95 in
Earth 978 feet, 4.5 in 1.0 in
Mars 1490 feet, 8.8 in 0.533 in
Jupiter 5090 feet, 3.7 in 11.221 in
Saturn 1 miles, 4068 feet 9.46 in
Uranus 3 miles, 2936 feet 4.012 in
Neptune 5 miles, 3011 feet 3.887 in
Pluto 7 miles, 1715 feet 0.178 in

Scaled speed of light: 1.337 mph