Astronomy SizeEarth Radii to Kilometers

Earth Radii to Kilometers

Snapshot

1 Earth Radius equals 6,371.0088 Kilometers. Conversion Encyclopedia uses the same fixed conversion basis across the calculator, common values, and reverse page for this page.

Reference basis: This conversion uses fixed astronomy size constants anchored to meters.
Example: For 2 Earth Radii, the result equals 12,742.0176 Kilometers.
Use the reverse page if you need the opposite direction with the same basis.

Use the interactive calculator below for custom values and the common-value table for quick checks.

Interactive conversion

Converter Calculator

6,371.0088 Kilometers (km)

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Machine access

Available to apps and AI agents

Earth Radii to Kilometers can be requested through Conversion Encyclopedia's structured interfaces by software and compatible AI agents. The identifiers below select the same calculation as the calculator.

Machine-readable identifiers

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

The JSON API and OpenAPI specification use the identifiers to reach the conversion engine. WebMCP lets compatible AI agents request the same calculation.

Example API request and response

POST /api/v1/convert

Request

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

Essential response

{
  "ok": true,
  "conversion": {
    "family": "astronomy-size",
    "value": 1,
    "from": "earth_radii",
    "to": "kilometers",
    "result": {
      "raw": 6371.0088,
      "display": "6,371.0088"
    },
    "canonicalPath": "/astronomy-size/earth-radii-to-kilometers/"
  }
}

Full API documentation

Explanation

This page converts Earth Radii into Kilometers using fixed astronomy size constants anchored to meters. The direct answer, calculator, and common values table all follow the same factor.

Formula: Kilometers = Earth Radii × 6,371.0088. Why: standard metric units are used as the common size basis, then planetary or stellar reference constants are applied to reach the target scale.

Earth Radii (R_earth): a planetary reference unit based on Earth's mean radius.

Kilometers (km): a practical metric unit for planetary and orbital size scales.

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

Because the route stays inside one meter-based reference model, the mirror page reverses the same constants without changing the underlying assumptions.

Method & Reference

Method basis: exact conversion formula shown in Snapshot.
Applied factor: 1 Earth Radius = 6,371.0088 Kilometers.
Consistency rule: calculator output and table values use the same constants and rounding policy.

Common Conversion Values

Earth Radii (R_earth)	Kilometers (km)
1	6,371.0088
2	12,742.0176
5	31,855.044
10	63,710.088
100	637,100.88
1,000	6,371,008.8

Questions & answers

Frequently Asked Questions

What is 1 earth radius in kilometers?

1 Earth Radius equals 6,371.0088 Kilometers on this page.

Does this Earth Radii to Kilometers 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 earth radii to kilometers?

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 Earth Radii to Kilometers?

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