Home › Unit Conversion › Astronomical units to Kilometers
Astronomical units to Kilometers (au to km)
Convert astronomical units to kilometers: 1 au = 149598000 km. Exact conversion factor, formula, 22-row table and worked examples, with JSON API and MCP access.
Formula
1 au = 149598000 km
kilometers = astronomical units × 149597870.7 — reverse: astronomical units = kilometers × 6.684587122e-9
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 au = 747989000 km
- 12.5 au = 1869970000 km
- 100 au = 14959800000 km
Astronomical units to kilometers conversion table
| Astronomical units (au) | Kilometers (km) |
|---|---|
| 1 | 149598000 |
| 2 | 299196000 |
| 3 | 448794000 |
| 4 | 598391000 |
| 5 | 747989000 |
| 6 | 897587000 |
| 7 | 1047190000 |
| 8 | 1196780000 |
| 9 | 1346380000 |
| 10 | 1495980000 |
| 15 | 2243970000 |
| 20 | 2991960000 |
| 25 | 3739950000 |
| 30 | 4487940000 |
| 40 | 5983910000 |
| 50 | 7479890000 |
| 75 | 11219800000 |
| 100 | 14959800000 |
| 200 | 29919600000 |
| 250 | 37399500000 |
| 500 | 74798900000 |
| 1000 | 149598000000 |
FAQ
How many kilometers are in one astronomical unit?
1 au = 149598000 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 astronomical units to kilometers?
Multiply the value in astronomical units by 149597870.7: kilometers = astronomical units × 149597870.7. For example, 5 au = 747989000 km.
How do I convert kilometers back to astronomical units?
Multiply by the inverse factor 6.684587122e-9 (astronomical units = kilometers × 6.684587122e-9), or use the kilometers-to-astronomical units page.
Related conversions
Machine access
- API:
GET https://tttkmbb.com/api/v1/convert?value=5&from_unit=au&to_unit=km - MCP: server
https://tttkmbb.com/mcp, toolconvert_unitswith{"value":5,"from_unit":"au","to_unit":"km"} - Markdown: https://tttkmbb.com/conversion/au-to-km.md · JSON: https://tttkmbb.com/conversion/au-to-km.json (add
?value=for a result) · Units: /api/v1/units?quantity=length - OpenAPI operationId:
convert_units. Freshness:static. Authentication: none.