Light Years to KM Converter
Convert light-years (ly) to kilometers (km) instantly. Type a value — the result updates as you type, and the swap button converts the other way.
Light Years to km formula
km = ly × 9460730472580.8
1 light-year = 9460730472580 kilometers · 1 kilometer = 0 light-years
To convert light-years to kilometers, multiply the value by 9460730472580.8. For example, 1 ly:
km = 1 × 9460730472580.8km = 9460730472580
So 1 ly = 9460730472580 km.
Mental math shortcut
Quick mental estimate: multiply by 9.5 trillion. For 1 ly that gives about 9500000000000 km — within 1% of the exact answer. Use the exact formula when precision matters.
Light Years to km conversion table
km back to Light Years
The same values converted the other way, rounded for everyday use:
| Kilometers | Light-years |
|---|---|
| 4730365236290 km | 0.5 ly |
| 9460730472580 km | 1 ly |
| 40113497203700 km | 4.24 ly |
| 81362282064200 km | 8.6 ly |
| 94607304725800 km | 10 ly |
| 946073047258000 km | 100 ly |
| 9460730472580000 km | 1000 ly |
About the units
Light-years (ly)
A light-year is the distance light travels in one Julian year: about 9.46 trillion kilometers or 5.88 trillion miles. It measures distances between stars.
Kilometers (km)
A kilometer is 1,000 meters. It is used for road distances and running races in most of the world.
Frequently asked questions
How many kilometers are in a light-year?
One light-year equals 9460730472580 kilometers.
What is 1 Light Years in km?
1 ly = 9460730472580 km.
How do I convert km back to Light Years?
Divide the kilometers by 9460730472580.8.