{
  "schemaVersion": 1,
  "slug": "km-miles-calculator",
  "category": "conversion",
  "kind": "implementation",
  "independentValidation": false,
  "implementationHash": "04afe09002b8d68907708c6f0af122f4a9ce12123d466756b46404db2d598a65",
  "provenance": "Generated from the calculation contract used by the published page. Publication is not external validation.",
  "sourceFiles": [
    "data/calculators/km-miles-calculator.json",
    "src/engine.js"
  ],
  "runtimeSource": "/sources/engine.txt",
  "runtimeHash": "5c888d8898afbdee36267bb9977829e1e2ac568f6677c8ee87469c139864645c",
  "scope": "The compute function records implemented equations, constants, lookup tables and custom rules. Inputs record defaults and allowed values; outputs record precision and units. Defaults are examples, not recommendations. General background references are not evidence for this specific algorithm.",
  "publishedFormula": {
    "formula": "mi = km ÷ 1.609344; km = mi × 1.609344; nmi = km ÷ 1.852",
    "vars": [
      [
        "km",
        "Kilometres"
      ],
      [
        "mi",
        "Statute miles"
      ],
      [
        "nmi",
        "Nautical miles"
      ],
      [
        "m",
        "Metres"
      ]
    ],
    "note": "Exact conversion factors; metres = km × 1000."
  },
  "externalEvidence": {
    "reviewedAt": "2026-10-04",
    "sources": [
      {
        "name": "NIST SP 811 — Conversion factors by quantity",
        "url": "https://www.nist.gov/pml/special-publication-811/nist-guide-si-appendix-b-conversion-factors/nist-guide-si-appendix-b9"
      }
    ],
    "basis": "1 international mile = 1.609344 km; 1 nautical mile = 1.852 km.",
    "limitations": "Only the displayed unit definitions are converted; rounding and measurement uncertainty are separate.",
    "implementationHash": "04afe09002b8d68907708c6f0af122f4a9ce12123d466756b46404db2d598a65",
    "domain": "conversion"
  },
  "contract": {
    "compute": "const F={\"km\":1,\"mi\":1.609344}, U={\"km\":\"km\",\"mi\":\"mi\"}, L={\"km2mi\":[\"km\",\"mi\"],\"mi2km\":[\"mi\",\"km\"]}; const pair=Object.prototype.hasOwnProperty.call(L,direction)?L[direction]:[from,to], source=pair[0], target=pair[1]; if(!Number.isFinite(value)||value<-1000000000||value>1000000000||!Object.prototype.hasOwnProperty.call(F,source)||!Object.prototype.hasOwnProperty.call(F,target))return {\"result\":null,\"metres\":null,\"nauticalMiles\":null,\"__error\":\"inputError\"}; const base=value*F[source], out=(function(value,direction){const km = direction === 'km2mi' ? value : value*1.609344; return { result: direction === 'km2mi' ? km/1.609344 : km, metres: km*1000, nauticalMiles: km/1.852 };})(base/F[\"km\"],\"km2mi\"); if(out.__error)return {...{\"result\":null,\"metres\":null,\"nauticalMiles\":null},...out}; out.result=value*(F[source]/F[target]);out.__resultUnit=U[target];out.__unitRatio=F[target]/F[source];return out;",
    "inputs": [
      {
        "name": "value",
        "type": "number",
        "default": 10,
        "min": -1000000000,
        "max": 1000000000,
        "step": 0.01,
        "requiredValue": true,
        "strictRange": true
      },
      {
        "name": "direction",
        "type": "select",
        "default": "auto",
        "options": [
          {
            "value": "auto"
          },
          {
            "value": "km2mi"
          },
          {
            "value": "mi2km"
          }
        ],
        "showWhen": {
          "from": []
        }
      },
      {
        "name": "precision",
        "type": "select",
        "default": 4,
        "options": [
          {
            "value": 0
          },
          {
            "value": 2
          },
          {
            "value": 4
          },
          {
            "value": 6
          }
        ]
      },
      {
        "name": "from",
        "type": "select",
        "default": "km",
        "options": [
          {
            "value": "km"
          },
          {
            "value": "mi"
          }
        ]
      },
      {
        "name": "to",
        "type": "select",
        "default": "mi",
        "options": [
          {
            "value": "mi"
          },
          {
            "value": "km"
          }
        ]
      }
    ],
    "outputs": [
      {
        "name": "result",
        "precision": 4,
        "unit": "",
        "precisionField": "precision",
        "unitField": "__resultUnit",
        "trimTrailingZeros": true,
        "notation": "auto"
      },
      {
        "name": "metres",
        "precision": 0,
        "unit": "m",
        "notation": "auto"
      },
      {
        "name": "nauticalMiles",
        "precision": 4,
        "unit": "nmi",
        "notation": "auto"
      }
    ],
    "interpret": null
  }
}