Kilometer to Light Year Converter
Convert Kilometer (km) to Light Year (ly) instantly. 1 km = 1.057001e-13 ly.
Length Converter
31 units available
1 km = 1.057001e-13 ly
Formula:
ly = km × 1.057001e-13With your value: 1 km = 1.057001e-13 ly
How big is that?
Everyday references on a logarithmic scale, all expressed in kilometer so you can sanity-check the result.
Other Kilometer to Light Year conversions
Kilometer to Light Year Conversion Table
| Kilometer (km) | Light Year (ly) |
|---|---|
| 0.5 | 5.285004e-14 |
| 1 | 1.057001e-13 |
| 2 | 2.114002e-13 |
| 5 | 5.285004e-13 |
| 10 | 1.057001e-12 |
| 15 | 1.585501e-12 |
| 20 | 2.114002e-12 |
| 25 | 2.642502e-12 |
| 50 | 5.285004e-12 |
| 100 | 1.057001e-11 |
| 250 | 2.642502e-11 |
| 500 | 5.285004e-11 |
| 1000 | 1.057001e-10 |
Light Year to Kilometer Conversion Table
| Light Year (ly) | Kilometer (km) |
|---|---|
| 0.5 | 4.730365e+12 |
| 1 | 9.460730e+12 |
| 2 | 1.892146e+13 |
| 5 | 4.730365e+13 |
| 10 | 9.460730e+13 |
| 15 | 1.419110e+14 |
| 20 | 1.892146e+14 |
| 25 | 2.365183e+14 |
| 50 | 4.730365e+14 |
| 100 | 9.460730e+14 |
| 250 | 2.365183e+15 |
| 500 | 4.730365e+15 |
| 1000 | 9.460730e+15 |
Where these values come from
Every factor on this page is traced to the document that defines it. See the full provenance dataset or our methodology.
Kilometer (km)
Length
Traceable to the metre, defined by fixing the speed of light in vacuum at 299 792 458 m/s. Imperial lengths derive from the 1959 international yard (0.9144 m exactly).
Source: BIPM, The International System of Units (SI), 9th edition, 2019 (updated 2024)
Bureau International des Poids et Mesures · Reviewed 2026-07-01
Light Year (ly)
Length
A light-year is the distance light travels in one Julian year: 9 460 730 472 580 800 m exactly.
Source: IAU Resolution B2 (2012) — definition of the astronomical unit; IAU B2 (2015) nominal values
International Astronomical Union · Reviewed 2026-07-01
How to Convert Kilometer to Light Year
To convert from Kilometer (km) to Light Year (ly), multiply the value by 1.057001e-13.
Formula: ly = km × 1.057001e-13
Reverse: km = ly × 9.460730e+12
Step-by-Step Example
- Start with your value in Kilometer. For example: 5 km
- Multiply by the conversion factor: 5 x 1.057001e-13
- The result is: 5.285004e-13 ly
About Kilometer
The kilometer equals 1,000 meters and is the standard unit for measuring distances between geographical locations in most countries.
Fun Fact: The circumference of Earth is approximately 40,075 km.
Common uses: road distances, geography, running.
About Light Year
A light year is the distance light travels through a vacuum in one Julian year — exactly 9,460,730,472,580,800 metres. It is a unit of distance, not of time.
Fun Fact: Proxima Centauri, the nearest star to the Sun, sits about 4.25 light years away.
Common uses: astronomy, popular science, education.
Frequently Asked Questions
How many Light Year are in 1 Kilometer?
There are exactly 1.057001e-13 Light Year in 1 Kilometer. This means the conversion factor from Kilometer to Light Year is 1.057001e-13.
What is the formula to convert Kilometer to Light Year?
The formula to convert Kilometer to Light Year is: ly = km × 1.057001e-13. For example, to convert 10 Kilometer to Light Year, you would multiply 10 by 1.057001e-13.
What is a Kilometer?
The kilometer equals 1,000 meters and is the standard unit for measuring distances between geographical locations in most countries.
What is a Light Year?
A light year is the distance light travels through a vacuum in one Julian year — exactly 9,460,730,472,580,800 metres. It is a unit of distance, not of time.
What are the common uses of Kilometer?
The Kilometer is commonly used in road distances, geography, running.
Related Length Conversions
Cite this page
UnitConvertLab. (2026). Kilometer to Light Year converter. UnitConvertLab. Retrieved from https://unitconvertlab.com/convert/kilometer-to-light_year