{
  "id": "target-heart-rate-calculator",
  "version": "2.0.0",
  "name": "Target Heart Rate Calculator",
  "shortName": "Target Heart Rate",
  "description": "Estimate maximum heart rate and five training zones with percentage-of-maximum or Karvonen heart-rate-reserve calculations.",
  "category": "Health & Fitness",
  "categorySlug": "health-fitness",
  "keywords": [
    "target heart rate",
    "heart rate zones",
    "Karvonen",
    "maximum heart rate",
    "training zones"
  ],
  "status": "live",
  "workStatus": "pending",
  "reviewStatus": "pending",
  "migrationStatus": "migrated",
  "migratedDate": "2026-08-25",
  "engine": "native",
  "creator": null,
  "reviewer": null,
  "quality": {
    "availability": "live",
    "technicalReviewRecord": "/reviews/target-heart-rate-calculator.json",
    "qualifiedReview": "pending",
    "qualifiedReviewer": null,
    "qualifiedReviewDate": null,
    "formulaVersion": "2.0.0",
    "referenceCoverage": "references-listed",
    "releaseTestScope": "Catalog and regression checks are not a professional formula audit; consult release evidence.",
    "historicalMetadataDate": "2026-08-25",
    "historicalMetadataNotice": "The imported date is not evidence of a completed human review."
  },
  "notice": "Heart-rate zones are estimates. Medicines, medical conditions, heat, altitude, and fitness can change a safe or appropriate range.",
  "urls": {
    "page": "/calculator/target-heart-rate-calculator/",
    "definition": "/calculator/target-heart-rate-calculator/definition.json",
    "schema": "/calculator/target-heart-rate-calculator/schema.json",
    "llms": "/calculator/target-heart-rate-calculator/llms.txt",
    "legacyDefinition": "/calculator/target-heart-rate-calculator.json"
  },
  "queryExample": "https://askcalculators.com/calculator/target-heart-rate-calculator/?age=35&maxMethod=estimated&formula=tanaka&useKarvonen=1&restingHeartRate=60",
  "queryParameters": {
    "age": {
      "label": "Age",
      "type": "number",
      "required": true,
      "default": 35
    },
    "maxMethod": {
      "label": "Maximum heart-rate input",
      "type": "select",
      "required": true,
      "default": "estimated"
    },
    "formula": {
      "label": "Age-based formula",
      "type": "select",
      "required": true,
      "default": "tanaka",
      "showWhen": {
        "field": "maxMethod",
        "equals": "estimated"
      }
    },
    "testedMax": {
      "label": "Tested maximum heart rate",
      "type": "number",
      "required": true,
      "default": 185,
      "showWhen": {
        "field": "maxMethod",
        "equals": "tested"
      }
    },
    "useKarvonen": {
      "label": "Use resting heart rate (Karvonen method)",
      "type": "checkbox",
      "required": false,
      "default": true
    },
    "restingHeartRate": {
      "label": "Resting heart rate",
      "type": "number",
      "required": true,
      "default": 60,
      "showWhen": {
        "field": "useKarvonen",
        "equals": true
      }
    }
  },
  "inputs": [
    {
      "id": "age",
      "label": "Age",
      "type": "number",
      "required": true,
      "defaultValue": 35,
      "min": 10,
      "max": 100,
      "step": 1,
      "suffix": "years",
      "width": "half"
    },
    {
      "id": "maxMethod",
      "label": "Maximum heart-rate input",
      "type": "select",
      "required": true,
      "defaultValue": "estimated",
      "options": [
        {
          "label": "Estimate from age",
          "value": "estimated"
        },
        {
          "label": "Use a tested maximum",
          "value": "tested"
        }
      ],
      "width": "half"
    },
    {
      "id": "formula",
      "label": "Age-based formula",
      "type": "select",
      "required": true,
      "defaultValue": "tanaka",
      "options": [
        {
          "label": "Tanaka: 208 − 0.7 × age",
          "value": "tanaka"
        },
        {
          "label": "Fox/Haskell: 220 − age",
          "value": "fox"
        },
        {
          "label": "Nes: 211 − 0.64 × age",
          "value": "nes"
        }
      ],
      "showWhen": {
        "field": "maxMethod",
        "equals": "estimated"
      },
      "width": "full"
    },
    {
      "id": "testedMax",
      "label": "Tested maximum heart rate",
      "type": "number",
      "required": true,
      "defaultValue": 185,
      "min": 60,
      "max": 240,
      "step": 1,
      "suffix": "bpm",
      "showWhen": {
        "field": "maxMethod",
        "equals": "tested"
      },
      "width": "full"
    },
    {
      "id": "useKarvonen",
      "label": "Use resting heart rate (Karvonen method)",
      "type": "checkbox",
      "defaultValue": true,
      "width": "full"
    },
    {
      "id": "restingHeartRate",
      "label": "Resting heart rate",
      "type": "number",
      "required": true,
      "defaultValue": 60,
      "min": 30,
      "max": 150,
      "step": 1,
      "suffix": "bpm",
      "showWhen": {
        "field": "useKarvonen",
        "equals": true
      },
      "width": "full"
    }
  ],
  "outputs": [
    {
      "id": "maxHeartRate",
      "label": "Maximum heart rate",
      "format": "integer",
      "primary": true,
      "suffix": " bpm"
    },
    {
      "id": "zone2",
      "label": "Moderate zone (60–70%)",
      "format": "text"
    },
    {
      "id": "vigorous",
      "label": "Vigorous range (70–85%)",
      "format": "text"
    },
    {
      "id": "method",
      "label": "Zone method",
      "format": "text"
    }
  ],
  "formula": {
    "expression": "Age-based MHR uses the selected formula; percentage method = MHR×intensity; Karvonen = resting HR + (MHR−resting HR)×intensity."
  },
  "examples": [
    {
      "label": "Reproducible default-input example (not a personal recommendation)",
      "inputs": {
        "age": 35,
        "maxMethod": "estimated",
        "formula": "tanaka",
        "testedMax": 185,
        "useKarvonen": true,
        "restingHeartRate": 60
      }
    }
  ],
  "sources": [
    {
      "label": "Calculator.net reference calculator",
      "url": "https://www.calculator.net/target-heart-rate-calculator.html"
    }
  ]
}