{
  "slug": "custom-met-calculator",
  "title": "Custom Activity MET Calculator",
  "category": "Energy Expenditure",
  "category_slug": "energy-expenditure",
  "tier": 3,
  "summary": "Estimate calories burned for any activity using its MET value, body weight, and duration.",
  "description": "This calculator estimates calories burned for any physical activity by applying the standard MET (Metabolic Equivalent of Task) equation from the Compendium of Physical Activities. It requires three inputs—the activity's MET value, body weight in kilograms, and duration in minutes—and outputs total energy expenditure in kilocalories based on the formula: Calories = MET × weight (kg) × time (hours). The estimate represents population-average energy cost and is most accurate when using validated MET values from published compendia for the specific activity performed.",
  "page_url": "https://fitmetriclab.com/en/tools/energy-expenditure/custom-met-calculator/",
  "api_url": "https://fitmetriclab.com/api/tools/custom-met-calculator.json",
  "formula": {
    "id": "custom_met_calculator",
    "expression": "\\text{Calories} = \\text{MET} \\times w \\times \\frac{t}{60}",
    "variables": [
      {
        "symbol": "\\text{MET}",
        "description": "MET value for the activity"
      },
      {
        "symbol": "w",
        "description": "Weight in kg"
      },
      {
        "symbol": "t",
        "description": "Duration in minutes"
      }
    ]
  },
  "inputs": [
    {
      "id": "met",
      "label": "MET Value",
      "type": "number",
      "unit": "",
      "default": 6,
      "min": 1,
      "max": 20,
      "step": 0.1
    },
    {
      "id": "weight_kg",
      "label": "Weight",
      "type": "number",
      "unit": "kg",
      "default": 75,
      "min": 20,
      "max": 300,
      "step": 0.1
    },
    {
      "id": "minutes",
      "label": "Duration",
      "type": "number",
      "unit": "min",
      "default": 60,
      "min": 1,
      "max": 300,
      "step": 1
    }
  ],
  "worked_example": {
    "inputs": {
      "met": 6,
      "weight_kg": 75,
      "minutes": 60
    },
    "expected_output": "450 kcal"
  },
  "result_summary_template": "An activity with a MET value of {met} performed for {minutes} minutes by someone weighing {weight_kg} burns {result}.",
  "methodology": "Applies the standard MET equation: Calories = MET × body weight (kg) × duration (hours). One MET is defined as 1 kcal/kg/hour, representing resting metabolic rate. Formula from Ainsworth et al., Compendium of Physical Activities (2011 update, Med Sci Sports Exerc).",
  "sources": [
    {
      "label": "Ainsworth BE, et al. 2011 Compendium of Physical Activities: A second update of codes and MET values. Med Sci Sports Exerc. 2011;43(8):1575–1581.",
      "url": "https://pubmed.ncbi.nlm.nih.gov/21681120/"
    },
    {
      "label": "Jetté M, Sidney K, Blümchen G. Metabolic equivalents (METS) in exercise testing, exercise prescription, and evaluation of functional capacity. Clin Cardiol. 1990;13(8):555–565.",
      "url": "https://pubmed.ncbi.nlm.nih.gov/2204507/"
    },
    {
      "label": "Compendium of Physical Activities (online database). Arizona State University Healthy Lifestyles Research Center.",
      "url": "https://sites.google.com/site/compendiumofphysicalactivities/"
    }
  ],
  "faqs": [
    {
      "question": "Where do I find MET values for different activities?",
      "answer": "The Compendium of Physical Activities, maintained by researchers at Arizona State University, catalogs MET values for hundreds of activities. The database is freely accessible online and includes codes for household chores, sports, occupational tasks, and recreational pursuits. MET values typically range from 1.0 for sedentary tasks to 18+ for very vigorous efforts."
    },
    {
      "question": "Why does the calculator use kilograms instead of pounds?",
      "answer": "The MET definition is standardized in metric units: 1 MET = 1 kcal/kg/hour. Using kilograms eliminates an intermediate conversion step and aligns with the scientific literature. Users measuring weight in pounds can divide by 2.205 to convert to kilograms before entering the value."
    },
    {
      "question": "Does fitness level affect the accuracy of MET-based estimates?",
      "answer": "Yes. More conditioned individuals often perform the same absolute workload with lower relative effort and sometimes lower total energy cost due to improved biomechanical efficiency. MET values in the Compendium represent average costs across heterogeneous study populations, so individual variation exists. The method remains useful for comparative purposes even when absolute accuracy varies."
    },
    {
      "question": "Can I use fractional MET values?",
      "answer": "The calculator accepts MET values in 0.1 increments, allowing input of published values like 4.3 METs for moderate-pace cycling or 8.5 METs for running at a 9-minute-mile pace. Fractional precision reflects the continuous nature of metabolic cost and matches the granularity reported in research literature."
    },
    {
      "question": "How does this calculator differ from activity-specific tools?",
      "answer": "Activity-specific calculators embed fixed MET values and may apply correction factors for speed, grade, or load. This custom MET tool requires the user to supply the MET value, offering flexibility for unusual activities or testing hypothetical scenarios. The underlying conversion formula is identical; only the input method differs."
    }
  ],
  "related_tools": [
    {
      "slug": "activity-comparison",
      "title": "Activity Calorie Comparison Calculator",
      "api_url": "https://fitmetriclab.com/api/tools/activity-comparison.json",
      "page_url": "https://fitmetriclab.com/en/tools/energy-expenditure/activity-comparison/"
    },
    {
      "slug": "calories-cycling",
      "title": "Calorie Burn — Cycling",
      "api_url": "https://fitmetriclab.com/api/tools/calories-cycling.json",
      "page_url": "https://fitmetriclab.com/en/tools/energy-expenditure/calories-cycling/"
    },
    {
      "slug": "calories-rowing",
      "title": "Calorie Burn — Rowing",
      "api_url": "https://fitmetriclab.com/api/tools/calories-rowing.json",
      "page_url": "https://fitmetriclab.com/en/tools/energy-expenditure/calories-rowing/"
    }
  ],
  "last_updated": "2026-04-22",
  "price": {
    "value": 0,
    "currency": "USD"
  },
  "runs_in_browser": true,
  "disclaimer": "Educational estimate produced from a published formula. Not medical, nutritional, or training advice. Calculations are deterministic — apply the formula to the inputs to reproduce the result."
}