Something like 150,000 light-years. The Milky Way is accompanied by several dwarf galaxies, like the Magellanic Clouds, that are relatively near by.
Traveling to another galaxy at the speed of light would take an incredibly long time. The closest galaxy to us, the Andromeda galaxy, is about 2.5 million light-years away. This means it would take 2.5 million years to reach Andromeda at the speed of light.
With current technology, it is not possible to travel to other galaxies due to the vast distances involved. The closest galaxy to our Milky Way is the Andromeda galaxy, but it is over 2 million light-years away. It would take millions of years to reach even the closest galaxy using current propulsion methods.
At the speed of light, it takes millions of years. For example, the Andromeda galaxy, which is the closest galaxy to our Milky Way galaxy, is about 2.5 million light years away, that is, traveling at light speed it would take 2.5 million years to get there.
The closest other galaxy to us would be the Canis Major Dwarf galaxy. It is only about 25,000 light years away (it is currently merging with the Milky Way).
The Canis Major Dwarf Galaxy is currently considered to be the closest galaxy to the Milky Way. It is 25,000 light years from our solar system and 42,000 light years from the center of the Milky Way. Its status as a galaxy is still disputed in some scientific circles. If the Canis Major Dwarf Galaxy loses its galaxy status, then the Sagittarius Dwarf Spheroidal Galaxy would reacquire the title as the Milky Way's closest neighbor. It is it is roughly 50,000 light years from the center of the Milky Way.
Our spiral galaxy of The Milky Way Galaxy is approximately 80,000 to 120,000 light-years across, and less than 7,000 light-years thick.
The Milky Way galaxy is about 100,000 light-years in diameter. Therefore, if you could travel at the speed of light, it would take approximately 100,000 years to traverse from one side of the galaxy to the other. However, this is a theoretical scenario, as traveling at the speed of light is not currently possible according to our understanding of physics.
Assuming you are referring to our Galaxy - The Milky Way. Light will take about 100,000 years to get from one side to the other.
The Milky Way galaxy is about 100,000 light-years in diameter. Since light travels at a speed of approximately 299,792 kilometers per second, it would take a ray of light about 100,000 years to travel from the sun to the edge of the Milky Way.
The Milky Way galaxy is about 100,000 light-years in diameter. If you could travel at the speed of light, it would take approximately 100,000 years to cross from one side of the galaxy to the other. However, this is a theoretical scenario, as current laws of physics suggest that nothing with mass can achieve the speed of light.
Time to reach a star is purely dependant on speed of travel. At light speed, you would travel approximately 1/10th of the galaxy. Well that number actually depends on what interpretation of the diameter of the Milky Way you subscribe. If travelling at the speed of Pioneer 10 (12km/s) (12*60*60*24*30*12*10000), in 10,000 years, you would have travelled approximately 0.39 light years, so you would have reached just 3.83 light years short of the closest star to Earth, Proxima Centauri.
8.31 minutes @ the speed of light.