{
    "name": "Garment Size Grade Calculator",
    "url": "https://calculators.geekmidst.com/calculators/garment-size-grade-calculator",
    "markdown": "https://calculators.geekmidst.com/calculators/garment-size-grade-calculator.md",
    "category": "Textile & apparel",
    "description": "Grade one garment measurement from the base size across a size range using your grade increments, with separate grades below and above the base.",
    "summary": "Grading adds a fixed increment for each size above the base and subtracts one for each size below. Enter the base measurement and your grade rule to get the full size spec.",
    "also_called": [
        "Pattern grading calculator",
        "Grade rule 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": "sizes",
            "label": "Size labels, smallest to largest",
            "type": "text",
            "default": "XS, S, M, L, XL, XXL"
        },
        {
            "name": "base_size",
            "label": "Base (sample) size",
            "type": "text",
            "default": "M"
        },
        {
            "name": "base_measurement",
            "label": "Base size measurement",
            "type": "number",
            "default": "100"
        },
        {
            "name": "grade_down",
            "label": "Grade per size below the base",
            "type": "number",
            "default": "4"
        },
        {
            "name": "grade_up",
            "label": "Grade per size above the base",
            "type": "number",
            "default": "5"
        }
    ],
    "outputs": [
        {
            "key": "size_list",
            "label": "Graded measurements",
            "format": "text"
        },
        {
            "key": "smallest",
            "label": "Smallest size",
            "format": "number"
        },
        {
            "key": "largest",
            "label": "Largest size",
            "format": "number"
        },
        {
            "key": "range",
            "label": "Spread across the range",
            "format": "number"
        }
    ],
    "formula": {
        "text": "Size k below base: M − k × Grade down;  size k above base: M + k × Grade up",
        "variables": {
            "M": "base size measurement",
            "k": "number of sizes away from the base",
            "Grade": "increment between neighbouring sizes"
        }
    },
    "worked_example": {
        "inputs": {
            "sizes": "XS, S, M, L, XL, XXL",
            "base_size": "M",
            "base_measurement": "100",
            "grade_down": "4",
            "grade_up": "5"
        },
        "steps": [
            "Below M: S = 100 − 4 = 96; XS = 100 − 2 × 4 = 92.",
            "Above M: L = 100 + 5 = 105; XL = 110; XXL = 115.",
            "Spread = 115 − 92 = 23."
        ],
        "result": "A 100 cm chest at size M grades to 92, 96, 100, 105, 110 and 115 cm from XS to XXL."
    },
    "interpretation": "Use it for one point of measure at a time (chest, waist, length). Body length, sleeve length and width usually have different grades.",
    "assumptions": [
        "Grading is linear: the same increment for every size step on each side of the base."
    ],
    "limitations": [
        "Grade rules are brand- and market-specific; enter your own. Pattern-point grading on CAD distributes the increment across several points."
    ],
    "rules": null,
    "faqs": [
        {
            "question": "Why have a different grade above and below?",
            "answer": "Many brands use a larger jump for bigger sizes (for example 4 cm below and 5–6 cm above) so larger sizes fit better."
        },
        {
            "question": "Can I use numeric sizes?",
            "answer": "Yes. Enter labels such as 36, 38, 40, 42 and pick one as the base."
        }
    ],
    "sources": [],
    "related": [
        {
            "name": "Apparel Order Quantity Breakdown Calculator",
            "url": "https://calculators.geekmidst.com/calculators/apparel-order-quantity-breakdown-calculator"
        },
        {
            "name": "Fabric Consumption per Garment Calculator",
            "url": "https://calculators.geekmidst.com/calculators/fabric-consumption-per-garment-calculator"
        },
        {
            "name": "Length Converter",
            "url": "https://calculators.geekmidst.com/calculators/length-converter"
        }
    ],
    "disclaimer": null,
    "publisher": "GM¹X CalcVerse"
}