Distance of all planets to the Sun in Astronomical units:
Mercury is 0.38
Venus is 0.72
Earth is 1.00
Mars is 1.52
Jupiter is 5.20
Saturn is 9.58
Uranus is 19.14
Neptune is 30.20
The best method for the calculation of the size of the solar system is by the creation of a scaled model of it which shows the distance of Sun and the eight planets.
The Earth and Sun is 93 million miles distance and is considered to be the Astronomical Unit which is being used by the Astronomers.