How many miles wide is our solar system?

Answer 1

It all depends on just what do you mean by solar system.
We can't use miles or meters to measure the solar system since it is so large. We have to use astronomical units. 1 AU is the average distance from the Earth to the Sun, or approximately 150 million kilometers or 93 million miles. If you could drive your car at highway speeds, from the Sun all the way out to Pluto, it would take you more than 6,000 years to complete the trip.

The true size of the Solar System is defined by the reach of its gravity; how far away an object can
still be said to orbit the Sun.

In the furthest reaches of the Solar System is the Oort Cloud; a cloud of icy objects that could orbit the Sun to a distance of 100,000 astronomical units, or 1.87 light-years away.
The Sun’s gravity dominates local space out to a distance of about 2 light-years, or almost half the
distance from the Sun to the nearest star: Proxima Centauri. Believe it or not, any object within
this region would probably be orbiting the Sun, and can be thought to be a part of the Solar System.

At those distances, it would take you 19 million years to complete the journey in a car to the edge
of the Solar System.