{
  "slug": "carb-cycling",
  "title": "Carb Cycling Calculator",
  "category": "Macros & Intake",
  "category_slug": "macros-intake",
  "tier": 3,
  "summary": "Estimate weekly calorie distribution across high-, medium-, and low-carb training days.",
  "description": "This calculator distributes weekly calorie intake across high-, medium-, and low-carb days by applying fixed multipliers to total daily energy expenditure (TDEE): 1.15× on high days, 1.00× on medium days, and 0.80× on low days. It requires TDEE and the number of days assigned to each carbohydrate tier, then outputs daily calorie targets for each tier and a seven-day average. The multipliers reflect moderate carb cycling protocols documented in practitioner literature and are intended for individuals aligning carbohydrate intake with training volume across the week.",
  "page_url": "https://fitmetriclab.com/en/tools/macros-intake/carb-cycling/",
  "api_url": "https://fitmetriclab.com/api/tools/carb-cycling.json",
  "formula": {
    "id": "carb_cycling",
    "expression": "\\text{kcal}_{high} = \\text{TDEE} \\times 1.15, \\quad \\text{kcal}_{med} = \\text{TDEE} \\times 1.00, \\quad \\text{kcal}_{low} = \\text{TDEE} \\times 0.80",
    "variables": [
      {
        "symbol": "\\text{TDEE}",
        "description": "Total daily energy expenditure"
      },
      {
        "symbol": "d_h",
        "description": "High-carb days per week"
      },
      {
        "symbol": "d_l",
        "description": "Low-carb days per week"
      },
      {
        "symbol": "d_m",
        "description": "Medium-carb days per week"
      }
    ]
  },
  "inputs": [
    {
      "id": "tdee",
      "label": "TDEE",
      "type": "number",
      "unit": "kcal",
      "default": 2500,
      "min": 800,
      "max": 6000,
      "step": 10
    },
    {
      "id": "high_days",
      "label": "High-Carb Days",
      "type": "number",
      "unit": "days",
      "default": 2,
      "min": 0,
      "max": 7,
      "step": 1
    },
    {
      "id": "low_days",
      "label": "Low-Carb Days",
      "type": "number",
      "unit": "days",
      "default": 3,
      "min": 0,
      "max": 7,
      "step": 1
    },
    {
      "id": "medium_days",
      "label": "Medium-Carb Days",
      "type": "number",
      "unit": "days",
      "default": 2,
      "min": 0,
      "max": 7,
      "step": 1
    }
  ],
  "worked_example": {
    "inputs": {
      "tdee": 2500,
      "high_days": 2,
      "low_days": 3,
      "medium_days": 2
    },
    "expected_output": "2,393 kcal/day avg"
  },
  "result_summary_template": "Given a TDEE of {tdee} kcal and a weekly split of {high_days} high-carb days, {medium_days} medium days, and {low_days} low days, the calculator estimates {result}.",
  "methodology": "Applies fixed multipliers to TDEE: high day = TDEE × 1.15, medium = TDEE × 1.00, low = TDEE × 0.80. Weekly total is summed and divided by 7 for daily average. Multipliers reflect moderate cycling ratios documented in practitioner protocols (McDonald, ISSN Position Stand on nutrient timing).",
  "sources": [
    {
      "label": "Aragon AA, Schoenfeld BJ, et al. International Society of Sports Nutrition Position Stand: Diets and Body Composition. J Int Soc Sports Nutr. 2017;14:16.",
      "url": "https://pubmed.ncbi.nlm.nih.gov/28630601/"
    },
    {
      "label": "Kerksick CM, Arent S, et al. International Society of Sports Nutrition Position Stand: Nutrient Timing. J Int Soc Sports Nutr. 2017;14:33.",
      "url": "https://pubmed.ncbi.nlm.nih.gov/28919842/"
    },
    {
      "label": "McDonald L. The Ultimate Diet 2.0. Lyle McDonald Publishing. 2003.",
      "url": "https://bodyrecomposition.com/"
    }
  ],
  "faqs": [
    {
      "question": "What do the 1.15 / 1.00 / 0.80 multipliers represent?",
      "answer": "These ratios set high days at 115% of TDEE, medium days at maintenance (100%), and low days at 80%. They reflect moderate carb-cycling protocols; more aggressive plans may use larger spreads, while conservative approaches stay closer to maintenance."
    },
    {
      "question": "Does this calculator specify grams of carbohydrate per day?",
      "answer": "No. It outputs total daily calorie targets for each day type. To determine carbohydrate grams, users must decide on protein and fat intakes, then allocate remaining calories to carbohydrate at 4 kcal per gram."
    },
    {
      "question": "How is TDEE used in the calculation?",
      "answer": "TDEE serves as the baseline for all day types. High days multiply TDEE by 1.15, medium days by 1.00, and low days by 0.80. The accuracy of the output depends entirely on the accuracy of the TDEE input."
    },
    {
      "question": "Can I use any combination of high, medium, and low days?",
      "answer": "Yes, provided the sum equals seven days per week. The calculator accepts any integer split from 0 to 7 for each category. Common patterns include 2 high / 2 medium / 3 low for strength athletes or 3 high / 2 medium / 2 low for endurance training blocks."
    },
    {
      "question": "Why is the result shown as an average daily intake?",
      "answer": "The tool sums the weekly calorie total and divides by seven to produce a mean. This average helps users compare overall energy balance across different cycling patterns while maintaining day-to-day variability in intake."
    }
  ],
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  ],
  "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."
}