What is the size of the largest asteroid?

The size of the largest asteroid is 592 miles or 952.76 kilometers in diameter. The asteroid's name is Ceres and it is also considered a dwarf planet.

Ceres is so large that it makes up one quarter of the total mass of the asteroid belt it calls home, which lies between Mars and Jupiter. It is large enough to be mostly spherical. Scientists believe that it has a rocky core enclosed in ice, which is in turn enclosed by a thin outer crust. Ceres has an eccentric orbit, which makes its distance from the sun vary between about 2.6 and nearly 3 astronomical units (each unit is roughly the distance from the Earth to the sun).