Astronomy SizeKilometers to Astronomical Units

Kilometers to Astronomical Units

Methodology·How We Verify

Snapshot

1 Kilometer equals 6.68e-9 Astronomical Units.

Reference basis: This conversion uses fixed astronomy size constants anchored to meters.
Example: For 2 Kilometers, the result equals 1.34e-8 Astronomical Units.

Interactive conversion

Converter Calculator

Decimals: 1.5 or 1,5. Fractions: 1/2. Scientific notation: 1e3. Write 1000 without grouping separators.

6.68e-9 Astronomical Units (AU)

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API and AI agent access

Kilometers to Astronomical Units.

Machine-readable identifiers

Conversion family: astronomy-size
Source unit: kilometers
Target unit: astronomical_units

Use these identifiers in the API request. Sources and model limits also apply to software clients.

Example API request and response

POST /api/v1/convert

Request

{
  "family": "astronomy-size",
  "value": 1,
  "from": "kilometers",
  "to": "astronomical_units"
}

Essential response

{
  "ok": true,
  "conversion": {
    "family": "astronomy-size",
    "value": 1,
    "from": "kilometers",
    "to": "astronomical_units",
    "result": {
      "raw": 6.68458712227e-9,
      "display": "6.68e-9"
    },
    "canonicalPath": "/astronomy-size/kilometers-to-astronomical-units/"
  }
}

API, OpenAPI and WebMCP documentation

Explanation

Kilometers convert into astronomical units using fixed astronomy size constants anchored to meters. Formula: AU = km × 6.68458712227e-9. That keeps the snapshot, calculator, table, and mirror page aligned on one constant basis.

It is useful for comparing planetary, stellar, and orbital-scale size references without switching between inconsistent reference tables.

Method & Reference

Method basis: exact conversion formula shown in Snapshot.
Applied factor: 1 Kilometer = 6.68e-9 Astronomical Units.
Consistency rule: calculator output and table values use the same constants and rounding policy.

Common Conversion Values

Kilometers (km)	Astronomical Units (AU)
1	6.68e-9
2	1.34e-8
5	3.34e-8
10	6.68e-8
100	6.68e-7
1000	0.000007

Questions & answers

Frequently Asked Questions

What is 1 kilometer in astronomical units?

1 Kilometer equals 6.68e-9 Astronomical Units on this page.

Does this Kilometers to Astronomical Units page convert through meters first?

Yes. Standard metric units act as the shared size basis, and the astronomy reference unit is then applied through its fixed meter constant.

When would I convert kilometers to astronomical units?

This route is useful when expressing planetary or stellar size references in metric units, or restating metric sizes in familiar astronomy reference scales.

How do I reverse Kilometers to Astronomical Units?

Use the mirror Astronomical Units to Kilometers route; it reverses the same astronomy size constants without changing the underlying assumptions.