{
  "entity_type": "unit_conversion_page",
  "id": "square-feet-to-acres",
  "name": "Square feet to Acres",
  "title": "Square feet to Acres Converter (ft² to acre)",
  "description": "Convert square feet to acres: 1 ft² = 0.0000229568 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": "ft2",
    "display": "ft²",
    "name": "square feet",
    "singular": "square foot"
  },
  "to_unit": {
    "symbol": "acre",
    "display": "acre",
    "name": "acres",
    "singular": "acre"
  },
  "linear": true,
  "factor": 0.00002295684114,
  "inverse_factor": 43560,
  "formula": "acres = square feet × 0.00002295684114",
  "reverse_formula": "square feet = acres × 43560",
  "unit_relation": "1 ft² = 0.0000229568 acre",
  "examples": [
    {
      "value": 5,
      "result": 0.000114784,
      "text": "5 ft² = 0.000114784 acre"
    },
    {
      "value": 12.5,
      "result": 0.000286961,
      "text": "12.5 ft² = 0.000286961 acre"
    },
    {
      "value": 100,
      "result": 0.00229568,
      "text": "100 ft² = 0.00229568 acre"
    }
  ],
  "table": [
    {
      "ft2": 1,
      "acre": 0.0000229568
    },
    {
      "ft2": 2,
      "acre": 0.0000459137
    },
    {
      "ft2": 3,
      "acre": 0.0000688705
    },
    {
      "ft2": 4,
      "acre": 0.0000918274
    },
    {
      "ft2": 5,
      "acre": 0.000114784
    },
    {
      "ft2": 6,
      "acre": 0.000137741
    },
    {
      "ft2": 7,
      "acre": 0.000160698
    },
    {
      "ft2": 8,
      "acre": 0.000183655
    },
    {
      "ft2": 9,
      "acre": 0.000206612
    },
    {
      "ft2": 10,
      "acre": 0.000229568
    },
    {
      "ft2": 15,
      "acre": 0.000344353
    },
    {
      "ft2": 20,
      "acre": 0.000459137
    },
    {
      "ft2": 25,
      "acre": 0.000573921
    },
    {
      "ft2": 30,
      "acre": 0.000688705
    },
    {
      "ft2": 40,
      "acre": 0.000918274
    },
    {
      "ft2": 50,
      "acre": 0.00114784
    },
    {
      "ft2": 75,
      "acre": 0.00172176
    },
    {
      "ft2": 100,
      "acre": 0.00229568
    },
    {
      "ft2": 200,
      "acre": 0.00459137
    },
    {
      "ft2": 250,
      "acre": 0.00573921
    },
    {
      "ft2": 500,
      "acre": 0.0114784
    },
    {
      "ft2": 1000,
      "acre": 0.0229568
    }
  ],
  "faq": [
    {
      "q": "How many acres are in one square foot?",
      "a": "1 ft² = 0.0000229568 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 square feet to acres?",
      "a": "Multiply the value in square feet by 0.00002295684114: acres = square feet × 0.00002295684114. For example, 5 ft² = 0.000114784 acre."
    },
    {
      "q": "How do I convert acres back to square feet?",
      "a": "Multiply by the inverse factor 43560 (square feet = acres × 43560), or use the acres-to-square feet 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=ft2&to_unit=acre",
    "calculator": "https://tttkmbb.com/api/v1/calculate/area?value=5&from_unit=ft2&to_unit=acre",
    "mcp_tool": "convert_units",
    "mcp_arguments": {
      "value": 5,
      "from_unit": "ft2",
      "to_unit": "acre"
    }
  },
  "links": {
    "html": "https://tttkmbb.com/conversion/square-feet-to-acres",
    "markdown": "https://tttkmbb.com/conversion/square-feet-to-acres.md",
    "json": "https://tttkmbb.com/conversion/square-feet-to-acres.json",
    "reverse": "https://tttkmbb.com/conversion/acres-to-square-feet",
    "quantity_converter": "https://tttkmbb.com/conversion/area",
    "units": "https://tttkmbb.com/api/v1/units?quantity=area"
  },
  "timestamp": "2026-09-24"
}