WeightStones to Kilograms

Stones to Kilograms

Updated: July 25, 2026 · Source: NIST Guide to the SI, Appendix B (Authoritative SI and U.S. customary conversion-factor reference.)

Methodology·How We Verify

Snapshot

1 stone equals exactly 6.35029318 kilograms.

Reference basis: Multiply stone by 6.35029318 to obtain kilograms.
Example: For 10 stone, the result is 63.5029318 kilograms.
Source basis: NIST Guide to the SI, Appendix B.

Interactive conversion

Converter Calculator

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

6.35 Kilograms

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API and AI agent access

Stones to Kilograms.

Machine-readable identifiers

Conversion family: weight
Source unit: stone
Target unit: kilogram

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": "weight",
  "value": 1,
  "from": "stone",
  "to": "kilogram"
}

Essential response

{
  "ok": true,
  "conversion": {
    "family": "weight",
    "value": 1,
    "from": "stone",
    "to": "kilogram",
    "result": {
      "raw": 6.35029318,
      "display": "6.35"
    },
    "canonicalPath": "/weight/stones-to-kilograms/"
  }
}

API, OpenAPI and WebMCP documentation

Explanation

One stone equals exactly 6.35029318 kilograms. Stone is still commonly used for body weight in the United Kingdom and Ireland, and it contains 14 avoirdupois pounds, so the kilogram value follows from the exact international pound definition.

Multiply stone by 6.35029318 to obtain kilograms.

Conversion Basis

Multiply stone by 6.35029318 to obtain kilograms.
For 10 stone, the result is 63.5029318 kilograms.
The snapshot, calculator, common values, and reverse route use the same conversion basis.
Source: NIST Guide to the SI, Appendix B (Authoritative SI and U.S. customary conversion-factor reference.)

Reference & Scope

The conversion uses 14 avoirdupois pounds per stone and the exact international pound-to-kilogram definition.

Source: NIST Guide to the SI, Appendix B (Authoritative SI and U.S. customary conversion-factor reference.)

Common Conversion Values

Stones	Kilograms
1	6.35
5	31.751
8	50.802
9	57.153
10	63.503
11	69.853
12	76.204
14	88.904

Questions & answers

Frequently Asked Questions

What is 1 stone in kilograms?

1 Stone equals 6.35 Kilograms on this page.

Is there a reverse Kilograms to Stones page?

Use the mirror Kilograms to Stones page to switch the direction while keeping the same fixed mass definitions.