Home › Unit Conversion › Light-years to Kilometers
Light-years to Kilometers (ly to km)
Convert light-years to kilometers: 1 ly = 9460730000000 km. Exact conversion factor, formula, 22-row table and worked examples, with JSON API and MCP access.
Formula
1 ly = 9460730000000 km
kilometers = light-years × 9460730473000 — reverse: light-years = kilometers × 1.057000834e-13
The factor is derived from the SI definitions of both units (base unit: m) as listed in NIST SP 811; results on this page are shown to 6 significant figures, the API returns up to 12.
Worked examples
- 5 ly = 47303700000000 km
- 12.5 ly = 118259000000000 km
- 100 ly = 946073000000000 km
Light-years to kilometers conversion table
| Light-years (ly) | Kilometers (km) |
|---|---|
| 1 | 9460730000000 |
| 2 | 18921500000000 |
| 3 | 28382200000000 |
| 4 | 37842900000000 |
| 5 | 47303700000000 |
| 6 | 56764400000000 |
| 7 | 66225100000000 |
| 8 | 75685800000000 |
| 9 | 85146600000000 |
| 10 | 94607300000000 |
| 15 | 141911000000000 |
| 20 | 189215000000000 |
| 25 | 236518000000000 |
| 30 | 283822000000000 |
| 40 | 378429000000000 |
| 50 | 473037000000000 |
| 75 | 709555000000000 |
| 100 | 946073000000000 |
| 200 | 1.89215e+15 |
| 250 | 2.36518e+15 |
| 500 | 4.73037e+15 |
| 1000 | 9.46073e+15 |
FAQ
How many kilometers are in one light-year?
1 ly = 9460730000000 km. The factor comes from the SI definitions of both units (NIST SP 811 / BIPM), so it is exact or correct to at least 10 significant figures.
What is the formula to convert light-years to kilometers?
Multiply the value in light-years by 9460730473000: kilometers = light-years × 9460730473000. For example, 5 ly = 47303700000000 km.
How do I convert kilometers back to light-years?
Multiply by the inverse factor 1.057000834e-13 (light-years = kilometers × 1.057000834e-13), or use the kilometers-to-light-years page.
Related conversions
Machine access
- API:
GET https://tttkmbb.com/api/v1/convert?value=5&from_unit=ly&to_unit=km - MCP: server
https://tttkmbb.com/mcp, toolconvert_unitswith{"value":5,"from_unit":"ly","to_unit":"km"} - Markdown: https://tttkmbb.com/conversion/light-years-to-km.md · JSON: https://tttkmbb.com/conversion/light-years-to-km.json (add
?value=for a result) · Units: /api/v1/units?quantity=length - OpenAPI operationId:
convert_units. Freshness:static. Authentication: none.