{
  "entity_type": "unit_conversion_page",
  "id": "hpa-to-inhg",
  "name": "Hectopascals to Inches of mercury",
  "title": "Hectopascals to Inches of mercury Converter (hPa to inHg)",
  "description": "Convert hectopascals to inches of mercury: 1 hPa = 0.02953 inHg. 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": "hPa",
    "display": "hPa",
    "name": "hectopascals",
    "singular": "hectopascal"
  },
  "to_unit": {
    "symbol": "inHg",
    "display": "inHg",
    "name": "inches of mercury",
    "singular": "inch of mercury"
  },
  "linear": true,
  "factor": 0.0295299833,
  "inverse_factor": 33.8638864,
  "formula": "inches of mercury = hectopascals × 0.0295299833",
  "reverse_formula": "hectopascals = inches of mercury × 33.8638864",
  "unit_relation": "1 hPa = 0.02953 inHg",
  "examples": [
    {
      "value": 5,
      "result": 0.14765,
      "text": "5 hPa = 0.14765 inHg"
    },
    {
      "value": 12.5,
      "result": 0.369125,
      "text": "12.5 hPa = 0.369125 inHg"
    },
    {
      "value": 100,
      "result": 2.953,
      "text": "100 hPa = 2.953 inHg"
    }
  ],
  "table": [
    {
      "hPa": 1,
      "inHg": 0.02953
    },
    {
      "hPa": 2,
      "inHg": 0.05906
    },
    {
      "hPa": 3,
      "inHg": 0.0885899
    },
    {
      "hPa": 4,
      "inHg": 0.11812
    },
    {
      "hPa": 5,
      "inHg": 0.14765
    },
    {
      "hPa": 6,
      "inHg": 0.17718
    },
    {
      "hPa": 7,
      "inHg": 0.20671
    },
    {
      "hPa": 8,
      "inHg": 0.23624
    },
    {
      "hPa": 9,
      "inHg": 0.26577
    },
    {
      "hPa": 10,
      "inHg": 0.2953
    },
    {
      "hPa": 15,
      "inHg": 0.44295
    },
    {
      "hPa": 20,
      "inHg": 0.5906
    },
    {
      "hPa": 25,
      "inHg": 0.73825
    },
    {
      "hPa": 30,
      "inHg": 0.885899
    },
    {
      "hPa": 40,
      "inHg": 1.1812
    },
    {
      "hPa": 50,
      "inHg": 1.4765
    },
    {
      "hPa": 75,
      "inHg": 2.21475
    },
    {
      "hPa": 100,
      "inHg": 2.953
    },
    {
      "hPa": 200,
      "inHg": 5.906
    },
    {
      "hPa": 250,
      "inHg": 7.3825
    },
    {
      "hPa": 500,
      "inHg": 14.765
    },
    {
      "hPa": 1000,
      "inHg": 29.53
    }
  ],
  "faq": [
    {
      "q": "How many inches of mercury are in one hectopascal?",
      "a": "1 hPa = 0.02953 inHg. 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 hectopascals to inches of mercury?",
      "a": "Multiply the value in hectopascals by 0.0295299833: inches of mercury = hectopascals × 0.0295299833. For example, 5 hPa = 0.14765 inHg."
    },
    {
      "q": "How do I convert inches of mercury back to hectopascals?",
      "a": "Multiply by the inverse factor 33.8638864 (hectopascals = inches of mercury × 33.8638864), or use the inches of mercury-to-hectopascals 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=hPa&to_unit=inHg",
    "calculator": "https://tttkmbb.com/api/v1/calculate/pressure?value=5&from_unit=hPa&to_unit=inHg",
    "mcp_tool": "convert_units",
    "mcp_arguments": {
      "value": 5,
      "from_unit": "hPa",
      "to_unit": "inHg"
    }
  },
  "links": {
    "html": "https://tttkmbb.com/conversion/hpa-to-inhg",
    "markdown": "https://tttkmbb.com/conversion/hpa-to-inhg.md",
    "json": "https://tttkmbb.com/conversion/hpa-to-inhg.json",
    "reverse": "https://tttkmbb.com/conversion/inhg-to-hpa",
    "quantity_converter": "https://tttkmbb.com/conversion/pressure",
    "units": "https://tttkmbb.com/api/v1/units?quantity=pressure"
  },
  "timestamp": "2026-09-24"
}