{
  "entity_type": "unit_conversion_page",
  "id": "kmh-to-mach",
  "name": "Kilometers per hour to Mach (sea level)",
  "title": "Kilometers per hour to Mach (sea level) Converter (km/h to mach)",
  "description": "Convert kilometers per hour to Mach (sea level): 1 km/h = 0.000816288 mach. Exact conversion factor, formula, 22-row table and worked examples, with JSON API and MCP access.",
  "quantity": "speed",
  "quantity_name": "Speed",
  "base_unit": "m/s",
  "from_unit": {
    "symbol": "km/h",
    "display": "km/h",
    "name": "kilometers per hour",
    "singular": "kilometer per hour"
  },
  "to_unit": {
    "symbol": "mach",
    "display": "mach",
    "name": "Mach (sea level)",
    "singular": "Mach"
  },
  "linear": true,
  "factor": 0.0008162876153,
  "inverse_factor": 1225.0584,
  "formula": "Mach (sea level) = kilometers per hour × 0.0008162876153",
  "reverse_formula": "kilometers per hour = Mach (sea level) × 1225.0584",
  "unit_relation": "1 km/h = 0.000816288 mach",
  "examples": [
    {
      "value": 5,
      "result": 0.00408144,
      "text": "5 km/h = 0.00408144 mach"
    },
    {
      "value": 12.5,
      "result": 0.0102036,
      "text": "12.5 km/h = 0.0102036 mach"
    },
    {
      "value": 100,
      "result": 0.0816288,
      "text": "100 km/h = 0.0816288 mach"
    }
  ],
  "table": [
    {
      "km/h": 1,
      "mach": 0.000816288
    },
    {
      "km/h": 2,
      "mach": 0.00163258
    },
    {
      "km/h": 3,
      "mach": 0.00244886
    },
    {
      "km/h": 4,
      "mach": 0.00326515
    },
    {
      "km/h": 5,
      "mach": 0.00408144
    },
    {
      "km/h": 6,
      "mach": 0.00489773
    },
    {
      "km/h": 7,
      "mach": 0.00571401
    },
    {
      "km/h": 8,
      "mach": 0.0065303
    },
    {
      "km/h": 9,
      "mach": 0.00734659
    },
    {
      "km/h": 10,
      "mach": 0.00816288
    },
    {
      "km/h": 15,
      "mach": 0.0122443
    },
    {
      "km/h": 20,
      "mach": 0.0163258
    },
    {
      "km/h": 25,
      "mach": 0.0204072
    },
    {
      "km/h": 30,
      "mach": 0.0244886
    },
    {
      "km/h": 40,
      "mach": 0.0326515
    },
    {
      "km/h": 50,
      "mach": 0.0408144
    },
    {
      "km/h": 75,
      "mach": 0.0612216
    },
    {
      "km/h": 100,
      "mach": 0.0816288
    },
    {
      "km/h": 200,
      "mach": 0.163258
    },
    {
      "km/h": 250,
      "mach": 0.204072
    },
    {
      "km/h": 500,
      "mach": 0.408144
    },
    {
      "km/h": 1000,
      "mach": 0.816288
    }
  ],
  "faq": [
    {
      "q": "How many Mach (sea level) are in one kilometer per hour?",
      "a": "1 km/h = 0.000816288 mach. 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 kilometers per hour to Mach (sea level)?",
      "a": "Multiply the value in kilometers per hour by 0.0008162876153: Mach (sea level) = kilometers per hour × 0.0008162876153. For example, 5 km/h = 0.00408144 mach."
    },
    {
      "q": "How do I convert Mach (sea level) back to kilometers per hour?",
      "a": "Multiply by the inverse factor 1225.0584 (kilometers per hour = Mach (sea level) × 1225.0584), or use the Mach (sea level)-to-kilometers per hour 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=km%2Fh&to_unit=mach",
    "calculator": "https://tttkmbb.com/api/v1/calculate/speed?value=5&from_unit=km%2Fh&to_unit=mach",
    "mcp_tool": "convert_units",
    "mcp_arguments": {
      "value": 5,
      "from_unit": "km/h",
      "to_unit": "mach"
    }
  },
  "links": {
    "html": "https://tttkmbb.com/conversion/kmh-to-mach",
    "markdown": "https://tttkmbb.com/conversion/kmh-to-mach.md",
    "json": "https://tttkmbb.com/conversion/kmh-to-mach.json",
    "reverse": "https://tttkmbb.com/conversion/mach-to-kmh",
    "quantity_converter": "https://tttkmbb.com/conversion/speed",
    "units": "https://tttkmbb.com/api/v1/units?quantity=speed"
  },
  "timestamp": "2026-09-24"
}