{
  "entity_type": "unit_conversion_page",
  "id": "foot-pounds-to-joules",
  "name": "Foot-pounds to Joules",
  "title": "Foot-pounds to Joules Converter (ft·lbf to J)",
  "description": "Convert foot-pounds to joules: 1 ft·lbf = 1.35582 J. Exact conversion factor, formula, 22-row table and worked examples, with JSON API and MCP access.",
  "quantity": "energy",
  "quantity_name": "Energy",
  "base_unit": "J",
  "from_unit": {
    "symbol": "ft_lbf",
    "display": "ft·lbf",
    "name": "foot-pounds",
    "singular": "foot-pound"
  },
  "to_unit": {
    "symbol": "J",
    "display": "J",
    "name": "joules",
    "singular": "joule"
  },
  "linear": true,
  "factor": 1.355817948,
  "inverse_factor": 0.7375621493,
  "formula": "joules = foot-pounds × 1.355817948",
  "reverse_formula": "foot-pounds = joules × 0.7375621493",
  "unit_relation": "1 ft·lbf = 1.35582 J",
  "examples": [
    {
      "value": 5,
      "result": 6.77909,
      "text": "5 ft·lbf = 6.77909 J"
    },
    {
      "value": 12.5,
      "result": 16.9477,
      "text": "12.5 ft·lbf = 16.9477 J"
    },
    {
      "value": 100,
      "result": 135.582,
      "text": "100 ft·lbf = 135.582 J"
    }
  ],
  "table": [
    {
      "ft_lbf": 1,
      "J": 1.35582
    },
    {
      "ft_lbf": 2,
      "J": 2.71164
    },
    {
      "ft_lbf": 3,
      "J": 4.06745
    },
    {
      "ft_lbf": 4,
      "J": 5.42327
    },
    {
      "ft_lbf": 5,
      "J": 6.77909
    },
    {
      "ft_lbf": 6,
      "J": 8.13491
    },
    {
      "ft_lbf": 7,
      "J": 9.49073
    },
    {
      "ft_lbf": 8,
      "J": 10.8465
    },
    {
      "ft_lbf": 9,
      "J": 12.2024
    },
    {
      "ft_lbf": 10,
      "J": 13.5582
    },
    {
      "ft_lbf": 15,
      "J": 20.3373
    },
    {
      "ft_lbf": 20,
      "J": 27.1164
    },
    {
      "ft_lbf": 25,
      "J": 33.8954
    },
    {
      "ft_lbf": 30,
      "J": 40.6745
    },
    {
      "ft_lbf": 40,
      "J": 54.2327
    },
    {
      "ft_lbf": 50,
      "J": 67.7909
    },
    {
      "ft_lbf": 75,
      "J": 101.686
    },
    {
      "ft_lbf": 100,
      "J": 135.582
    },
    {
      "ft_lbf": 200,
      "J": 271.164
    },
    {
      "ft_lbf": 250,
      "J": 338.954
    },
    {
      "ft_lbf": 500,
      "J": 677.909
    },
    {
      "ft_lbf": 1000,
      "J": 1355.82
    }
  ],
  "faq": [
    {
      "q": "How many joules are in one foot-pound?",
      "a": "1 ft·lbf = 1.35582 J. 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 foot-pounds to joules?",
      "a": "Multiply the value in foot-pounds by 1.355817948: joules = foot-pounds × 1.355817948. For example, 5 ft·lbf = 6.77909 J."
    },
    {
      "q": "How do I convert joules back to foot-pounds?",
      "a": "Multiply by the inverse factor 0.7375621493 (foot-pounds = joules × 0.7375621493), or use the joules-to-foot-pounds 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=ft_lbf&to_unit=J",
    "calculator": "https://tttkmbb.com/api/v1/calculate/energy?value=5&from_unit=ft_lbf&to_unit=J",
    "mcp_tool": "convert_units",
    "mcp_arguments": {
      "value": 5,
      "from_unit": "ft_lbf",
      "to_unit": "J"
    }
  },
  "links": {
    "html": "https://tttkmbb.com/conversion/foot-pounds-to-joules",
    "markdown": "https://tttkmbb.com/conversion/foot-pounds-to-joules.md",
    "json": "https://tttkmbb.com/conversion/foot-pounds-to-joules.json",
    "reverse": "https://tttkmbb.com/conversion/joules-to-foot-pounds",
    "quantity_converter": "https://tttkmbb.com/conversion/energy",
    "units": "https://tttkmbb.com/api/v1/units?quantity=energy"
  },
  "timestamp": "2026-09-24"
}