This chart compares the sizes of some of the biggest known galaxies. You can directly compare the size of the Milky Way Galaxy or the Andromeda Galaxy with IC 1101, the largest known galaxy. IC 1101 is a supergiant elliptical galaxy with a diameter of approximately 6 million light years and roughly 100 trillion stars. IC 1101 is about 1 billion light years away from the Milky Way. We have another chart comparing several other large galaxies as well as one chart comparing smaller galaxies.