{
  "entity_type": "unit_conversion_page",
  "id": "square-km-to-square-miles",
  "name": "Square kilometers to Square miles",
  "title": "Square kilometers to Square miles Converter (km² to mi²)",
  "description": "Convert square kilometers to square miles: 1 km² = 0.386102 mi². Exact conversion factor, formula, 22-row table and worked examples, with JSON API and MCP access.",
  "quantity": "area",
  "quantity_name": "Area",
  "base_unit": "m2",
  "from_unit": {
    "symbol": "km2",
    "display": "km²",
    "name": "square kilometers",
    "singular": "square kilometer"
  },
  "to_unit": {
    "symbol": "mi2",
    "display": "mi²",
    "name": "square miles",
    "singular": "square mile"
  },
  "linear": true,
  "factor": 0.3861021585,
  "inverse_factor": 2.58998811,
  "formula": "square miles = square kilometers × 0.3861021585",
  "reverse_formula": "square kilometers = square miles × 2.58998811",
  "unit_relation": "1 km² = 0.386102 mi²",
  "examples": [
    {
      "value": 5,
      "result": 1.93051,
      "text": "5 km² = 1.93051 mi²"
    },
    {
      "value": 12.5,
      "result": 4.82628,
      "text": "12.5 km² = 4.82628 mi²"
    },
    {
      "value": 100,
      "result": 38.6102,
      "text": "100 km² = 38.6102 mi²"
    }
  ],
  "table": [
    {
      "km2": 1,
      "mi2": 0.386102
    },
    {
      "km2": 2,
      "mi2": 0.772204
    },
    {
      "km2": 3,
      "mi2": 1.15831
    },
    {
      "km2": 4,
      "mi2": 1.54441
    },
    {
      "km2": 5,
      "mi2": 1.93051
    },
    {
      "km2": 6,
      "mi2": 2.31661
    },
    {
      "km2": 7,
      "mi2": 2.70272
    },
    {
      "km2": 8,
      "mi2": 3.08882
    },
    {
      "km2": 9,
      "mi2": 3.47492
    },
    {
      "km2": 10,
      "mi2": 3.86102
    },
    {
      "km2": 15,
      "mi2": 5.79153
    },
    {
      "km2": 20,
      "mi2": 7.72204
    },
    {
      "km2": 25,
      "mi2": 9.65255
    },
    {
      "km2": 30,
      "mi2": 11.5831
    },
    {
      "km2": 40,
      "mi2": 15.4441
    },
    {
      "km2": 50,
      "mi2": 19.3051
    },
    {
      "km2": 75,
      "mi2": 28.9577
    },
    {
      "km2": 100,
      "mi2": 38.6102
    },
    {
      "km2": 200,
      "mi2": 77.2204
    },
    {
      "km2": 250,
      "mi2": 96.5255
    },
    {
      "km2": 500,
      "mi2": 193.051
    },
    {
      "km2": 1000,
      "mi2": 386.102
    }
  ],
  "faq": [
    {
      "q": "How many square miles are in one square kilometer?",
      "a": "1 km² = 0.386102 mi². 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 square kilometers to square miles?",
      "a": "Multiply the value in square kilometers by 0.3861021585: square miles = square kilometers × 0.3861021585. For example, 5 km² = 1.93051 mi²."
    },
    {
      "q": "How do I convert square miles back to square kilometers?",
      "a": "Multiply by the inverse factor 2.58998811 (square kilometers = square miles × 2.58998811), or use the square miles-to-square kilometers 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=km2&to_unit=mi2",
    "calculator": "https://tttkmbb.com/api/v1/calculate/area?value=5&from_unit=km2&to_unit=mi2",
    "mcp_tool": "convert_units",
    "mcp_arguments": {
      "value": 5,
      "from_unit": "km2",
      "to_unit": "mi2"
    }
  },
  "links": {
    "html": "https://tttkmbb.com/conversion/square-km-to-square-miles",
    "markdown": "https://tttkmbb.com/conversion/square-km-to-square-miles.md",
    "json": "https://tttkmbb.com/conversion/square-km-to-square-miles.json",
    "reverse": "https://tttkmbb.com/conversion/square-miles-to-square-km",
    "quantity_converter": "https://tttkmbb.com/conversion/area",
    "units": "https://tttkmbb.com/api/v1/units?quantity=area"
  },
  "timestamp": "2026-09-24"
}