{
  "entity_type": "unit_conversion_page",
  "id": "hectares-to-acres",
  "name": "Hectares to Acres",
  "title": "Hectares to Acres Converter (ha to acre)",
  "description": "Convert hectares to acres: 1 ha = 2.47105 acre. 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": "ha",
    "display": "ha",
    "name": "hectares",
    "singular": "hectare"
  },
  "to_unit": {
    "symbol": "acre",
    "display": "acre",
    "name": "acres",
    "singular": "acre"
  },
  "linear": true,
  "factor": 2.471053815,
  "inverse_factor": 0.4046856422,
  "formula": "acres = hectares × 2.471053815",
  "reverse_formula": "hectares = acres × 0.4046856422",
  "unit_relation": "1 ha = 2.47105 acre",
  "examples": [
    {
      "value": 5,
      "result": 12.3553,
      "text": "5 ha = 12.3553 acre"
    },
    {
      "value": 12.5,
      "result": 30.8882,
      "text": "12.5 ha = 30.8882 acre"
    },
    {
      "value": 100,
      "result": 247.105,
      "text": "100 ha = 247.105 acre"
    }
  ],
  "table": [
    {
      "ha": 1,
      "acre": 2.47105
    },
    {
      "ha": 2,
      "acre": 4.94211
    },
    {
      "ha": 3,
      "acre": 7.41316
    },
    {
      "ha": 4,
      "acre": 9.88422
    },
    {
      "ha": 5,
      "acre": 12.3553
    },
    {
      "ha": 6,
      "acre": 14.8263
    },
    {
      "ha": 7,
      "acre": 17.2974
    },
    {
      "ha": 8,
      "acre": 19.7684
    },
    {
      "ha": 9,
      "acre": 22.2395
    },
    {
      "ha": 10,
      "acre": 24.7105
    },
    {
      "ha": 15,
      "acre": 37.0658
    },
    {
      "ha": 20,
      "acre": 49.4211
    },
    {
      "ha": 25,
      "acre": 61.7763
    },
    {
      "ha": 30,
      "acre": 74.1316
    },
    {
      "ha": 40,
      "acre": 98.8422
    },
    {
      "ha": 50,
      "acre": 123.553
    },
    {
      "ha": 75,
      "acre": 185.329
    },
    {
      "ha": 100,
      "acre": 247.105
    },
    {
      "ha": 200,
      "acre": 494.211
    },
    {
      "ha": 250,
      "acre": 617.763
    },
    {
      "ha": 500,
      "acre": 1235.53
    },
    {
      "ha": 1000,
      "acre": 2471.05
    }
  ],
  "faq": [
    {
      "q": "How many acres are in one hectare?",
      "a": "1 ha = 2.47105 acre. 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 hectares to acres?",
      "a": "Multiply the value in hectares by 2.471053815: acres = hectares × 2.471053815. For example, 5 ha = 12.3553 acre."
    },
    {
      "q": "How do I convert acres back to hectares?",
      "a": "Multiply by the inverse factor 0.4046856422 (hectares = acres × 0.4046856422), or use the acres-to-hectares 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=ha&to_unit=acre",
    "calculator": "https://tttkmbb.com/api/v1/calculate/area?value=5&from_unit=ha&to_unit=acre",
    "mcp_tool": "convert_units",
    "mcp_arguments": {
      "value": 5,
      "from_unit": "ha",
      "to_unit": "acre"
    }
  },
  "links": {
    "html": "https://tttkmbb.com/conversion/hectares-to-acres",
    "markdown": "https://tttkmbb.com/conversion/hectares-to-acres.md",
    "json": "https://tttkmbb.com/conversion/hectares-to-acres.json",
    "reverse": "https://tttkmbb.com/conversion/acres-to-hectares",
    "quantity_converter": "https://tttkmbb.com/conversion/area",
    "units": "https://tttkmbb.com/api/v1/units?quantity=area"
  },
  "timestamp": "2026-09-24"
}