{
  "id": "stone-and-lbs-to-kg",
  "version": "2532c500cfd5",
  "status": "published",
  "name": "Stone and Pounds to Kg Converter",
  "question": "Stone and pounds to kg converter",
  "summary": "Converts stone and pounds to kilograms: kg = (st × 14 + lb) × 0.45359237.",
  "category": "convert",
  "subcategory": "weight",
  "url": "https://www.acalculator.org/convert/stone-and-lbs-to-kg",
  "markdown": "https://www.acalculator.org/convert/stone-and-lbs-to-kg.md",
  "kind": "formulas",
  "method": "kg = (st × 14 + lb) × 0.45359237",
  "assumptions": [
    "1 stone = 14 lb (NIST Handbook 44, Appendix C) and 1 lb = 0.45359237 kg exactly (NIST SP 811), so 1 stone = 6.35029318 kg. Pounds may be 14 or more.",
    "Exact on the typed decimals: at most 6 decimal places (6 significant digits below 0.0001), rounded half up."
  ],
  "inputs": {
    "$schema": "https://json-schema.org/draft/2020-12/schema",
    "type": "object",
    "properties": {
      "value": {
        "title": "Stone (st)",
        "description": "The whole stone.",
        "type": "number",
        "minimum": 0,
        "maximum": 1000000000000
      },
      "lb": {
        "title": "Pounds (lb)",
        "description": "The pounds on top of the stone.",
        "type": "number",
        "minimum": 0,
        "maximum": 1000000000000
      },
      "result": {
        "title": "Kilograms (kg)",
        "description": "The weight in kilograms.",
        "type": "number",
        "minimum": 0,
        "maximum": 6350293180000
      }
    }
  },
  "solve": {
    "fillAny": 2,
    "variables": [
      "value",
      "lb",
      "result"
    ],
    "inputsOnly": []
  },
  "outputs": {
    "value": {
      "label": "Stone (st)",
      "description": "The whole stone.",
      "format": "number"
    },
    "lb": {
      "label": "Pounds (lb)",
      "description": "The pounds on top of the stone.",
      "format": "number"
    },
    "result": {
      "label": "Kilograms (kg)",
      "description": "The weight in kilograms.",
      "format": "number"
    }
  },
  "defaultAnswer": {
    "inputs": {
      "value": 11,
      "lb": 4
    },
    "outputs": {
      "result": 71.66759446
    },
    "text": "11 st 4 lb = 71.667594 kg."
  },
  "examples": [
    {
      "given": {
        "value": 11,
        "lb": 4
      },
      "expect": {
        "result": 71.66759446
      },
      "source": "NIST Handbook 44 (2026), Appendix C: 1 stone = 14 lb; NIST SP 811 (2008), Appendix B.8: 1 lb = 0.45359237 kg"
    },
    {
      "given": {
        "value": 1,
        "lb": 0
      },
      "expect": {
        "result": 6.35029318
      },
      "source": "NIST Handbook 44 (2026), Appendix C: 1 stone = 14 lb; NIST SP 811 (2008), Appendix B.8: 1 lb = 0.45359237 kg"
    },
    {
      "given": {
        "value": 10,
        "lb": 7
      },
      "expect": {
        "result": 66.67807839
      },
      "source": "NIST Handbook 44 (2026), Appendix C: 1 stone = 14 lb; NIST SP 811 (2008), Appendix B.8: 1 lb = 0.45359237 kg"
    }
  ],
  "sources": [
    "NIST SP 811 (2008), Guide for the Use of the International System of Units, Table 5 (SI prefixes) and Appendix B.8 (factors for units listed alphabetically), retrieved 2026-10-05. https://www.nist.gov/pml/special-publication-811",
    "NIST Handbook 44 (2026), Appendix C, General Tables of Units of Measurement: British avoirdupois units, 14 pounds = 1 stone, retrieved 2026-10-05. https://www.nist.gov/document/2026-nist-handbook-44-appendix-c"
  ],
  "related": [
    "stone-to-kg",
    "kg-to-stone",
    "lbs-to-kg"
  ],
  "changelog": []
}