Hubble Science Image Utilized in "Touch the Universe" - Saturn
The semi-major axis of Saturn's orbit about the Sun is 9.5 astronomical units or roughly 890 million miles (1.4 billion km).
The planet (without rings) has a diameter of roughly 75,000 miles (120,000 km) at the equator.
NASA and Erich Karkoschka (University of Arizona)
Image from PR1998-18, "Hubble Space Telescope Completes Eighth Year of Exploration"