{
    "name": "Protein Calculator",
    "url": "https://calculators.geekmidst.com/calculators/protein-calculator",
    "markdown": "https://calculators.geekmidst.com/calculators/protein-calculator.md",
    "category": "Health & fitness",
    "description": "Work out daily protein in grams from your body weight: the 0.8 g/kg adult RDA, the ISSN 1.4–2.0 g/kg range for exercisers, or your own figure.",
    "summary": "Protein needs are set per kilogram of body weight. The adult RDA of 0.8 g/kg is a minimum; people who train regularly are usually advised 1.4–2.0 g/kg.",
    "also_called": [
        "Protein intake calculator",
        "Daily protein 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": "weight",
            "label": "Body weight",
            "type": "number",
            "default": "70"
        },
        {
            "name": "unit",
            "label": "Unit",
            "type": "segmented",
            "default": "kg",
            "options": {
                "kg": "kg",
                "lb": "lb"
            }
        },
        {
            "name": "goal",
            "label": "Recommendation",
            "type": "select",
            "default": "exercise",
            "options": {
                "rda": "General adult RDA (0.8 g/kg)",
                "exercise": "Regular exercise (ISSN 1.4–2.0 g/kg)",
                "custom": "My own g/kg figure"
            }
        },
        {
            "name": "custom_gkg",
            "label": "Protein per kg",
            "type": "number",
            "default": "1.2",
            "unit": "g/kg",
            "shown_when": {
                "goal": "custom"
            }
        },
        {
            "name": "meals",
            "label": "Meals per day",
            "type": "number",
            "default": "3"
        }
    ],
    "outputs": [
        {
            "key": "protein_range",
            "label": "Daily protein",
            "format": "text"
        },
        {
            "key": "protein_low",
            "label": "Lower end",
            "format": "integer"
        },
        {
            "key": "protein_high",
            "label": "Upper end",
            "format": "integer"
        },
        {
            "key": "per_meal",
            "label": "Per meal (mid-point ÷ meals)",
            "format": "integer"
        },
        {
            "key": "per_meal_issn",
            "label": "ISSN per-meal dose (0.25 g/kg)",
            "format": "integer"
        },
        {
            "key": "rda",
            "label": "Adult RDA for comparison",
            "format": "integer"
        }
    ],
    "formula": {
        "text": "Protein (g/day) = body weight (kg) × g/kg;  RDA = 0.8 g/kg;  ISSN = 1.4–2.0 g/kg;  per meal = 0.25 g/kg",
        "variables": {
            "body weight": "in kg (1 lb = 0.45359237 kg)",
            "g/kg": "grams of protein per kilogram of body weight per day"
        }
    },
    "worked_example": {
        "inputs": {
            "weight": "80",
            "unit": "kg",
            "goal": "exercise",
            "custom_gkg": "1.2",
            "meals": "4"
        },
        "steps": [
            "Lower: 80 × 1.4 = 112 g; upper: 80 × 2.0 = 160 g.",
            "RDA for comparison: 80 × 0.8 = 64 g.",
            "ISSN per-meal dose: 80 × 0.25 = 20 g."
        ],
        "result": "An 80 kg person who trains regularly would aim for about 112–160 g of protein a day, roughly 20–40 g per meal."
    },
    "interpretation": "Use the range as a daily target averaged over the week, spread across meals. The RDA covers basic needs for most healthy adults; higher intakes mainly help people doing resistance or endurance training.",
    "assumptions": [
        "You are a healthy adult (the RDA of 0.8 g/kg applies to adults).",
        "Body weight is a reasonable proxy for lean mass; at high body fat, using a goal or lean-mass weight may be more appropriate."
    ],
    "limitations": [
        "Not for people with kidney disease, who may need protein restriction, or for pregnancy, breastfeeding or children, whose needs differ.",
        "The ISSN range comes from studies of exercising people; it is not a requirement for sedentary adults."
    ],
    "rules": null,
    "faqs": [
        {
            "question": "Is 0.8 g/kg enough?",
            "answer": "It meets the basic needs of most healthy adults and is best read as a minimum rather than an optimum. People who train regularly are usually advised more."
        },
        {
            "question": "Should I eat more than 2 g/kg?",
            "answer": "The ISSN says 1.4–2.0 g/kg is sufficient for most exercising people, and notes that intakes above 3 g/kg may help body composition in resistance-trained individuals. Anyone with kidney disease should follow medical advice instead."
        }
    ],
    "sources": [
        {
            "title": "ISSN Position Stand: protein and exercise (2017), abstract",
            "url": "https://cdr.lib.unc.edu/concern/articles/jd473011s"
        },
        {
            "title": "Harvard Health: How much protein do you need every day?",
            "url": "https://health.harvard.edu/blog/how-much-protein-do-you-need-every-day-201506188096"
        }
    ],
    "related": [
        {
            "name": "Fat Intake Calculator",
            "url": "https://calculators.geekmidst.com/calculators/fat-intake-calculator"
        },
        {
            "name": "TDEE Calculator",
            "url": "https://calculators.geekmidst.com/calculators/tdee-calculator"
        },
        {
            "name": "BMR Calculator",
            "url": "https://calculators.geekmidst.com/calculators/bmr-calculator"
        },
        {
            "name": "One Rep Max Calculator",
            "url": "https://calculators.geekmidst.com/calculators/one-rep-max-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"
}