Since there are no physical boundaries in space, the solar system is often regarded as the distance from the sun to Neptune, which is approximately 30 astronomical units and equals approximately 2,790,000,000 miles. Astronomical units, which are used by astronomers, each equal 93 million miles.
Pluto and other icy objects in the Kuiper Belt are called dwarf planets and whilw some solar system measurements include Pluto, others do not. Pluto's distance from the sun varies a great deal, as it has an elliptical orbit that causes it to be closer to the sun than Neptune at times. At an average distance, Pluto is 3,666,000,000 miles from the sun.