{
  "slug": "wallpaper-calculator",
  "title": "Wallpaper Calculator",
  "heading": "Wallpaper Roll & Cost Calculator",
  "category": "other",
  "url": "https://www.revenuelab.fyi/toolbox/wallpaper-calculator",
  "summary": "Rolls needed accounting for pattern repeat and waste.",
  "description": "Pattern repeat is what wrecks wallpaper budgets. A 21 in repeat can cost you nearly a foot of waste on every drop.",
  "formula": "Drops per roll = roll length ÷ (wall height + repeat); rolls = total drops ÷ drops per roll.",
  "dateModified": "2026-09-30",
  "run_url": "https://www.revenuelab.fyi/api/public/calc?tool=wallpaper-calculator",
  "inputs": [
    {
      "id": "perimeter",
      "label": "Room perimeter",
      "kind": "number",
      "hint": null,
      "default": 48,
      "unit": "ft",
      "min": 1,
      "max": null
    },
    {
      "id": "height",
      "label": "Wall height",
      "kind": "number",
      "hint": null,
      "default": 8,
      "unit": "ft",
      "min": 4,
      "max": null
    },
    {
      "id": "rollW",
      "label": "Roll width",
      "kind": "number",
      "hint": null,
      "default": 20.5,
      "unit": "in",
      "min": 10,
      "max": null
    },
    {
      "id": "rollL",
      "label": "Roll length",
      "kind": "number",
      "hint": null,
      "default": 33,
      "unit": "ft",
      "min": 5,
      "max": null
    },
    {
      "id": "repeat",
      "label": "Pattern repeat",
      "kind": "number",
      "hint": null,
      "default": 12,
      "unit": "in",
      "min": 0,
      "max": 36
    },
    {
      "id": "price",
      "label": "Price per roll",
      "kind": "number",
      "hint": null,
      "default": 65,
      "unit": "$",
      "min": 0,
      "max": null
    }
  ],
  "outputs": [
    {
      "id": "rolls",
      "label": "Rolls to buy",
      "format": "number",
      "hint": null,
      "primary": true
    },
    {
      "id": "cost",
      "label": "Wallpaper cost",
      "format": "currency",
      "hint": null,
      "primary": false
    },
    {
      "id": "drops",
      "label": "Strips (drops) needed",
      "format": "number",
      "hint": null,
      "primary": false
    },
    {
      "id": "perRoll",
      "label": "Drops per roll",
      "format": "number",
      "hint": null,
      "primary": false
    },
    {
      "id": "dropLen",
      "label": "Cut length per drop (ft)",
      "format": "decimal",
      "hint": null,
      "primary": false
    },
    {
      "id": "wastePct",
      "label": "Leftover waste (%)",
      "format": "decimal",
      "hint": null,
      "primary": false
    }
  ],
  "worked_example": {
    "inputs": [
      "Room perimeter: 48 ft",
      "Wall height: 8 ft",
      "Roll width: 20.5 in",
      "Roll length: 33 ft",
      "Pattern repeat: 12 in",
      "Price per roll: 65 $"
    ],
    "outputs": [
      "Rolls to buy: 10",
      "Wallpaper cost: $650",
      "Strips (drops) needed: 29",
      "Drops per roll: 3",
      "Cut length per drop (ft): 9",
      "Leftover waste (%): 3.3"
    ]
  },
  "how_to": {
    "title": "How to use this",
    "steps": [
      "Enter room perimeter (ft).",
      "Enter wall height (ft).",
      "Enter roll width (in).",
      "Enter roll length (ft).",
      "Enter pattern repeat (in).",
      "Enter price per roll ($).",
      "Read your rolls to buy on the right — it updates as you type.",
      "Hit Share to keep the scenario or send it to someone."
    ]
  },
  "scenarios": [
    {
      "name": "Conservative",
      "description": "Lower-end numbers — what if things land soft?",
      "values": {
        "perimeter": 29,
        "height": 8,
        "rollW": 12.299999999999999,
        "rollL": 20,
        "repeat": 7,
        "price": 39
      }
    },
    {
      "name": "Typical",
      "description": "Defaults — the most common real-world setup.",
      "values": {
        "perimeter": 48,
        "height": 8,
        "rollW": 20.5,
        "rollL": 33,
        "repeat": 12,
        "price": 65
      }
    },
    {
      "name": "Ambitious",
      "description": "Higher-end numbers — what if things really pop?",
      "values": {
        "perimeter": 77,
        "height": 8,
        "rollW": 32.800000000000004,
        "rollL": 53,
        "repeat": 19,
        "price": 104
      }
    }
  ],
  "limitations": [
    "Estimates assume standard, average conditions — local rules, pricing, and materials vary.",
    "Results are rounded for readability; add a buffer before ordering, booking, or committing.",
    "Double-check anything with a real cost attached against a local quote."
  ],
  "faq": [
    {
      "q": "How does the wallpaper roll & cost calculator work?",
      "a": "Pattern repeat is what wrecks wallpaper budgets. A 21 in repeat can cost you nearly a foot of waste on every drop. The underlying maths is: Drops per roll = roll length ÷ (wall height + repeat); rolls = total drops ÷ drops per roll."
    },
    {
      "q": "What do I need to enter?",
      "a": "6 values: room perimeter, wall height, roll width, roll length, pattern repeat, and price per roll. Each field starts with a sensible default, so you can change one number at a time and watch the result move."
    },
    {
      "q": "What does the rolls to buy result mean?",
      "a": "It is returned as a whole number and updates live as you edit the inputs, so you can compare two or three versions of a scenario in a few seconds."
    },
    {
      "q": "Is this calculator free, and do I need an account?",
      "a": "Yes, it's free, and no account is required. Nothing you type is stored on our servers — the maths runs entirely in your browser."
    },
    {
      "q": "How accurate is the result?",
      "a": "It applies the standard formula exactly, so the arithmetic is precise. Estimates assume standard, average conditions — local rules, pricing, and materials vary."
    },
    {
      "q": "Who is this tool for?",
      "a": "It's built for anyone doing everyday planning maths — a quick estimate that would otherwise need four browser tabs and a calculator app."
    }
  ],
  "related": [
    "https://www.revenuelab.fyi/toolbox/paint-coverage",
    "https://www.revenuelab.fyi/toolbox/drywall-calculator"
  ],
  "license": "CC-BY-4.0",
  "citation": "RevenueLab — Wallpaper Calculator (https://www.revenuelab.fyi/toolbox/wallpaper-calculator)"
}