{
    "name": "Drywall Sheet Count Calculator",
    "url": "https://calculators.geekmidst.com/calculators/drywall-sheet-count-calculator",
    "markdown": "https://calculators.geekmidst.com/calculators/drywall-sheet-count-calculator.md",
    "category": "Construction",
    "description": "Count drywall or plasterboard sheets for a room’s walls and ceiling from its size, openings and sheet size (4×8, 4×12 ft or 1200 mm boards), with waste.",
    "summary": "Add the wall area (perimeter × height, less openings) and the ceiling, add a waste allowance, and divide by the area of one sheet.",
    "also_called": [
        "Plasterboard calculator",
        "Sheetrock calculator",
        "Gypsum board 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": "units",
            "label": "Units",
            "type": "segmented",
            "default": "imperial",
            "options": {
                "metric": "Metric",
                "imperial": "Imperial"
            }
        },
        {
            "name": "length",
            "label": "Room length",
            "type": "number",
            "default": "12"
        },
        {
            "name": "width",
            "label": "Room width",
            "type": "number",
            "default": "10"
        },
        {
            "name": "height",
            "label": "Wall height",
            "type": "number",
            "default": "8"
        },
        {
            "name": "openings",
            "label": "Doors and windows (total area)",
            "type": "number",
            "default": "40",
            "optional": true
        },
        {
            "name": "ceiling",
            "label": "Include the ceiling",
            "type": "segmented",
            "default": "yes",
            "options": {
                "yes": "Yes",
                "no": "No"
            }
        },
        {
            "name": "sheet",
            "label": "Sheet size",
            "type": "select",
            "default": "4x8",
            "options": {
                "4x8": "4 × 8 ft",
                "4x10": "4 × 10 ft",
                "4x12": "4 × 12 ft",
                "1200x2400": "1200 × 2400 mm",
                "1200x2700": "1200 × 2700 mm",
                "1200x3000": "1200 × 3000 mm"
            }
        },
        {
            "name": "waste",
            "label": "Waste allowance",
            "type": "number",
            "default": "10",
            "unit": "%",
            "optional": true
        }
    ],
    "outputs": [
        {
            "key": "sheets",
            "label": "Sheets to buy",
            "format": "integer"
        },
        {
            "key": "sheets_no_waste",
            "label": "Sheets of area (no waste)",
            "format": "number"
        },
        {
            "key": "area_ft2",
            "label": "Total area",
            "format": "number"
        },
        {
            "key": "area_m2",
            "label": "Total area",
            "format": "number"
        },
        {
            "key": "wall_area_ft2",
            "label": "Wall area",
            "format": "number"
        },
        {
            "key": "ceiling_area_ft2",
            "label": "Ceiling area",
            "format": "number"
        }
    ],
    "formula": {
        "text": "Area = 2(L + W) × H − Openings (+ L × W);  Sheets = ⌈Area × (1 + Waste) ÷ Sheet area⌉",
        "variables": {
            "L, W, H": "room length, width and wall height",
            "Sheet area": "e.g. 4 × 8 ft = 32 ft², 1.2 × 2.4 m = 2.88 m²"
        }
    },
    "worked_example": {
        "inputs": {
            "units": "imperial",
            "length": "12",
            "width": "10",
            "height": "8",
            "openings": "40",
            "ceiling": "yes",
            "sheet": "4x8",
            "waste": "10"
        },
        "steps": [
            "Walls = 2 × (12 + 10) × 8 = 352 ft² − 40 ft² openings = 312 ft².",
            "Plus ceiling 12 × 10 = 120 ft² → 432 ft².",
            "432 × 1.10 ÷ 32 ft² = 14.85 → 15 sheets."
        ],
        "result": "A 12 × 10 ft room with 8 ft walls and its ceiling needs 15 sheets of 4 × 8 drywall with 10% waste."
    },
    "interpretation": "Longer sheets mean fewer joints to tape; boards for ceilings and wet areas may be a different type. Buy screws, tape and compound by area too.",
    "assumptions": [
        "One layer of board on each surface."
    ],
    "limitations": [
        "Sloped ceilings, soffits and bulkheads need to be added separately."
    ],
    "rules": null,
    "faqs": [
        {
            "question": "Should I subtract doors and windows?",
            "answer": "Subtract large openings, but many installers leave small windows in because the cut-outs are mostly waste anyway."
        },
        {
            "question": "Which size should I buy?",
            "answer": "Choose a length that spans the wall height or ceiling width with fewest joints, provided you can carry it into the room."
        }
    ],
    "sources": [],
    "related": [
        {
            "name": "Paint Coverage Calculator",
            "url": "https://calculators.geekmidst.com/calculators/paint-coverage-calculator"
        },
        {
            "name": "Insulation R-Value Calculator",
            "url": "https://calculators.geekmidst.com/calculators/insulation-r-value-calculator"
        },
        {
            "name": "Wall Plastering Quantity Calculator",
            "url": "https://calculators.geekmidst.com/calculators/wall-plastering-quantity-calculator"
        }
    ],
    "disclaimer": "Quantities are estimates. Confirm requirements with your engineer or supplier before ordering materials.",
    "publisher": "GM¹X CalcVerse"
}