{
    "name": "Macro Calculator",
    "url": "https://calculators.geekmidst.com/calculators/macro-calculator",
    "markdown": "https://calculators.geekmidst.com/calculators/macro-calculator.md",
    "category": "Health & fitness",
    "description": "Turn a daily calorie target and a carb, protein and fat split into grams per day and per meal, checked against the adult AMDR ranges.",
    "summary": "Each macronutrient’s share of your calories, divided by its energy per gram (4 kcal for carbohydrate and protein, 9 kcal for fat), gives the grams to eat each day.",
    "also_called": [
        "Macronutrient calculator",
        "Macros calculator"
    ],
    "applies_to": "Worldwide",
    "last_updated": "2026-10-29",
    "computation": "Results are computed in the visitor’s browser on the HTML page. This API describes the calculator; it does not compute results.",
    "inputs": [
        {
            "name": "calories",
            "label": "Daily calories",
            "type": "number",
            "default": "2000",
            "unit": "kcal"
        },
        {
            "name": "carb_pct",
            "label": "Carbohydrate",
            "type": "number",
            "default": "50",
            "unit": "%"
        },
        {
            "name": "protein_pct",
            "label": "Protein",
            "type": "number",
            "default": "20",
            "unit": "%"
        },
        {
            "name": "fat_pct",
            "label": "Fat",
            "type": "number",
            "default": "30",
            "unit": "%"
        },
        {
            "name": "meals",
            "label": "Meals per day",
            "type": "number",
            "default": "3",
            "optional": true
        }
    ],
    "outputs": [
        {
            "key": "summary",
            "label": "Daily macros",
            "format": "text"
        },
        {
            "key": "carbs_g",
            "label": "Carbohydrate",
            "format": "integer"
        },
        {
            "key": "protein_g",
            "label": "Protein",
            "format": "integer"
        },
        {
            "key": "fat_g",
            "label": "Fat",
            "format": "integer"
        },
        {
            "key": "per_meal",
            "label": "Per meal",
            "format": "text"
        }
    ],
    "formula": {
        "text": "Carbs (g) = kcal × carb% ÷ 4;  Protein (g) = kcal × protein% ÷ 4;  Fat (g) = kcal × fat% ÷ 9",
        "variables": {
            "kcal": "daily calorie target",
            "4, 4, 9": "Atwater energy factors in kcal per gram"
        }
    },
    "worked_example": {
        "inputs": {
            "calories": "2000",
            "carb_pct": "50",
            "protein_pct": "20",
            "fat_pct": "30",
            "meals": "3"
        },
        "steps": [
            "Carbohydrate: 2,000 × 50% = 1,000 kcal ÷ 4 = 250 g.",
            "Protein: 2,000 × 20% = 400 kcal ÷ 4 = 100 g.",
            "Fat: 2,000 × 30% = 600 kcal ÷ 9 = 66.7 g, shown as 67 g.",
            "Over 3 meals: about 83 g carbs, 33 g protein and 22 g fat each."
        ],
        "result": "On 2,000 kcal a day with a 50/20/30 split you would eat about 250 g carbohydrate, 100 g protein and 67 g fat."
    },
    "interpretation": "The adult Acceptable Macronutrient Distribution Ranges (AMDR) are 45–65% of energy from carbohydrate, 10–35% from protein and 20–35% from fat. A split inside those ranges is consistent with the reference intakes; the calculator flags any share outside them. Food quality matters as much as the numbers.",
    "assumptions": [
        "Atwater general factors: 4 kcal/g carbohydrate, 4 kcal/g protein, 9 kcal/g fat.",
        "Alcohol and fibre are not counted separately.",
        "AMDR values are the IOM 2002/2005 adult ranges."
    ],
    "limitations": [
        "Food labels round values, so totals from real meals will differ by a few grams.",
        "Not a medical diet: people with diabetes, kidney disease or other conditions need individual advice."
    ],
    "rules": null,
    "faqs": [
        {
            "question": "What split should I choose?",
            "answer": "Any split inside the AMDR is consistent with the reference intakes for healthy adults. Within that, the best split is one that suits your training, preferences and any medical advice, and that you can keep to."
        },
        {
            "question": "Why is fat 9 kcal per gram?",
            "answer": "Fat stores more than twice the energy of carbohydrate or protein per gram, so the same share of calories gives fewer grams of fat."
        }
    ],
    "sources": [
        {
            "title": "National Academies: Acceptable Macronutrient Distribution Ranges (IOM 2002/2005), Table 3-1",
            "url": "https://www.nationalacademies.org/read/27957/chapter/5"
        }
    ],
    "related": [
        {
            "name": "Calorie Calculator",
            "url": "https://calculators.geekmidst.com/calculators/calorie-calculator"
        },
        {
            "name": "Carbohydrate Calculator",
            "url": "https://calculators.geekmidst.com/calculators/carbohydrate-calculator"
        },
        {
            "name": "BMR Calculator",
            "url": "https://calculators.geekmidst.com/calculators/bmr-calculator"
        },
        {
            "name": "Percentage Calculator",
            "url": "https://calculators.geekmidst.com/calculators/percentage-calculator"
        }
    ],
    "disclaimer": "This is a general screening estimate for adults, not medical advice or a diagnosis. Talk to a qualified health professional about your health.",
    "publisher": "GM¹X CalcVerse"
}