{
  "entity_type": "unit_conversion_page",
  "id": "inhg-to-hpa",
  "name": "Inches of mercury to Hectopascals",
  "title": "Inches of mercury to Hectopascals Converter (inHg to hPa)",
  "description": "Convert inches of mercury to hectopascals: 1 inHg = 33.8639 hPa. Exact conversion factor, formula, 22-row table and worked examples, with JSON API and MCP access.",
  "quantity": "pressure",
  "quantity_name": "Pressure",
  "base_unit": "Pa",
  "from_unit": {
    "symbol": "inHg",
    "display": "inHg",
    "name": "inches of mercury",
    "singular": "inch of mercury"
  },
  "to_unit": {
    "symbol": "hPa",
    "display": "hPa",
    "name": "hectopascals",
    "singular": "hectopascal"
  },
  "linear": true,
  "factor": 33.8638864,
  "inverse_factor": 0.0295299833,
  "formula": "hectopascals = inches of mercury × 33.8638864",
  "reverse_formula": "inches of mercury = hectopascals × 0.0295299833",
  "unit_relation": "1 inHg = 33.8639 hPa",
  "examples": [
    {
      "value": 5,
      "result": 169.319,
      "text": "5 inHg = 169.319 hPa"
    },
    {
      "value": 12.5,
      "result": 423.299,
      "text": "12.5 inHg = 423.299 hPa"
    },
    {
      "value": 100,
      "result": 3386.39,
      "text": "100 inHg = 3386.39 hPa"
    }
  ],
  "table": [
    {
      "inHg": 1,
      "hPa": 33.8639
    },
    {
      "inHg": 2,
      "hPa": 67.7278
    },
    {
      "inHg": 3,
      "hPa": 101.592
    },
    {
      "inHg": 4,
      "hPa": 135.456
    },
    {
      "inHg": 5,
      "hPa": 169.319
    },
    {
      "inHg": 6,
      "hPa": 203.183
    },
    {
      "inHg": 7,
      "hPa": 237.047
    },
    {
      "inHg": 8,
      "hPa": 270.911
    },
    {
      "inHg": 9,
      "hPa": 304.775
    },
    {
      "inHg": 10,
      "hPa": 338.639
    },
    {
      "inHg": 15,
      "hPa": 507.958
    },
    {
      "inHg": 20,
      "hPa": 677.278
    },
    {
      "inHg": 25,
      "hPa": 846.597
    },
    {
      "inHg": 30,
      "hPa": 1015.92
    },
    {
      "inHg": 40,
      "hPa": 1354.56
    },
    {
      "inHg": 50,
      "hPa": 1693.19
    },
    {
      "inHg": 75,
      "hPa": 2539.79
    },
    {
      "inHg": 100,
      "hPa": 3386.39
    },
    {
      "inHg": 200,
      "hPa": 6772.78
    },
    {
      "inHg": 250,
      "hPa": 8465.97
    },
    {
      "inHg": 500,
      "hPa": 16931.9
    },
    {
      "inHg": 1000,
      "hPa": 33863.9
    }
  ],
  "faq": [
    {
      "q": "How many hectopascals are in one inch of mercury?",
      "a": "1 inHg = 33.8639 hPa. 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 inches of mercury to hectopascals?",
      "a": "Multiply the value in inches of mercury by 33.8638864: hectopascals = inches of mercury × 33.8638864. For example, 5 inHg = 169.319 hPa."
    },
    {
      "q": "How do I convert hectopascals back to inches of mercury?",
      "a": "Multiply by the inverse factor 0.0295299833 (inches of mercury = hectopascals × 0.0295299833), or use the hectopascals-to-inches of mercury 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=inHg&to_unit=hPa",
    "calculator": "https://tttkmbb.com/api/v1/calculate/pressure?value=5&from_unit=inHg&to_unit=hPa",
    "mcp_tool": "convert_units",
    "mcp_arguments": {
      "value": 5,
      "from_unit": "inHg",
      "to_unit": "hPa"
    }
  },
  "links": {
    "html": "https://tttkmbb.com/conversion/inhg-to-hpa",
    "markdown": "https://tttkmbb.com/conversion/inhg-to-hpa.md",
    "json": "https://tttkmbb.com/conversion/inhg-to-hpa.json",
    "reverse": "https://tttkmbb.com/conversion/hpa-to-inhg",
    "quantity_converter": "https://tttkmbb.com/conversion/pressure",
    "units": "https://tttkmbb.com/api/v1/units?quantity=pressure"
  },
  "timestamp": "2026-09-24"
}