{
  "entity_type": "unit_conversion_page",
  "id": "stone-to-kg",
  "name": "Stone to Kilograms",
  "title": "Stone to Kilograms Converter (st to kg)",
  "description": "Convert stone to kilograms: 1 st = 6.35029 kg. Exact conversion factor, formula, 22-row table and worked examples, with JSON API and MCP access.",
  "quantity": "mass",
  "quantity_name": "Mass",
  "base_unit": "kg",
  "from_unit": {
    "symbol": "st",
    "display": "st",
    "name": "stone",
    "singular": "stone"
  },
  "to_unit": {
    "symbol": "kg",
    "display": "kg",
    "name": "kilograms",
    "singular": "kilogram"
  },
  "linear": true,
  "factor": 6.35029318,
  "inverse_factor": 0.1574730444,
  "formula": "kilograms = stone × 6.35029318",
  "reverse_formula": "stone = kilograms × 0.1574730444",
  "unit_relation": "1 st = 6.35029 kg",
  "examples": [
    {
      "value": 5,
      "result": 31.7515,
      "text": "5 st = 31.7515 kg"
    },
    {
      "value": 12.5,
      "result": 79.3787,
      "text": "12.5 st = 79.3787 kg"
    },
    {
      "value": 100,
      "result": 635.029,
      "text": "100 st = 635.029 kg"
    }
  ],
  "table": [
    {
      "st": 1,
      "kg": 6.35029
    },
    {
      "st": 2,
      "kg": 12.7006
    },
    {
      "st": 3,
      "kg": 19.0509
    },
    {
      "st": 4,
      "kg": 25.4012
    },
    {
      "st": 5,
      "kg": 31.7515
    },
    {
      "st": 6,
      "kg": 38.1018
    },
    {
      "st": 7,
      "kg": 44.4521
    },
    {
      "st": 8,
      "kg": 50.8023
    },
    {
      "st": 9,
      "kg": 57.1526
    },
    {
      "st": 10,
      "kg": 63.5029
    },
    {
      "st": 15,
      "kg": 95.2544
    },
    {
      "st": 20,
      "kg": 127.006
    },
    {
      "st": 25,
      "kg": 158.757
    },
    {
      "st": 30,
      "kg": 190.509
    },
    {
      "st": 40,
      "kg": 254.012
    },
    {
      "st": 50,
      "kg": 317.515
    },
    {
      "st": 75,
      "kg": 476.272
    },
    {
      "st": 100,
      "kg": 635.029
    },
    {
      "st": 200,
      "kg": 1270.06
    },
    {
      "st": 250,
      "kg": 1587.57
    },
    {
      "st": 500,
      "kg": 3175.15
    },
    {
      "st": 1000,
      "kg": 6350.29
    }
  ],
  "faq": [
    {
      "q": "How many kilograms are in one stone?",
      "a": "1 st = 6.35029 kg. 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."
    },
    {
      "q": "What is the formula to convert stone to kilograms?",
      "a": "Multiply the value in stone by 6.35029318: kilograms = stone × 6.35029318. For example, 5 st = 31.7515 kg."
    },
    {
      "q": "How do I convert kilograms back to stone?",
      "a": "Multiply by the inverse factor 0.1574730444 (stone = kilograms × 0.1574730444), or use the kilograms-to-stone page."
    }
  ],
  "sources": [
    {
      "name": "NIST Special Publication 811 – Guide for the Use of the International System of Units (SI), Appendix B conversion factors",
      "url": "https://www.nist.gov/pml/special-publication-811",
      "type": "standard",
      "retrieved_at": "2026-09-24"
    },
    {
      "name": "BIPM – The International System of Units (SI Brochure, 9th edition)",
      "url": "https://www.bipm.org/en/publications/si-brochure",
      "type": "standard",
      "retrieved_at": "2026-09-24"
    },
    {
      "name": "Wikipedia – Conversion of units",
      "url": "https://en.wikipedia.org/wiki/Conversion_of_units",
      "type": "reference",
      "retrieved_at": "2026-09-24"
    }
  ],
  "freshness": {
    "type": "static",
    "max_age_seconds": null,
    "note": "Fixed conversion factors (NIST/BIPM definitions); results never go stale."
  },
  "api": {
    "convert": "https://tttkmbb.com/api/v1/convert?value=5&from_unit=st&to_unit=kg",
    "calculator": "https://tttkmbb.com/api/v1/calculate/mass?value=5&from_unit=st&to_unit=kg",
    "mcp_tool": "convert_units",
    "mcp_arguments": {
      "value": 5,
      "from_unit": "st",
      "to_unit": "kg"
    }
  },
  "links": {
    "html": "https://tttkmbb.com/conversion/stone-to-kg",
    "markdown": "https://tttkmbb.com/conversion/stone-to-kg.md",
    "json": "https://tttkmbb.com/conversion/stone-to-kg.json",
    "reverse": "https://tttkmbb.com/conversion/kg-to-stone",
    "quantity_converter": "https://tttkmbb.com/conversion/mass",
    "units": "https://tttkmbb.com/api/v1/units?quantity=mass"
  },
  "timestamp": "2026-09-24"
}