{
  "slug": "paint-coverage",
  "title": "Paint Coverage Calculator",
  "heading": "Paint Gallons & Cost Calculator",
  "category": "other",
  "url": "https://www.revenuelab.fyi/toolbox/paint-coverage",
  "summary": "Gallons per coat, primer, and total paint spend.",
  "description": "One gallon covers roughly 350 sq ft on smooth drywall and closer to 250 sq ft on textured or porous surfaces. Two coats is the norm over a color change.",
  "formula": "Gallons = (wall area − openings) × coats ÷ coverage.",
  "dateModified": "2026-09-30",
  "run_url": "https://www.revenuelab.fyi/api/public/calc?tool=paint-coverage",
  "inputs": [
    {
      "id": "perimeter",
      "label": "Room perimeter",
      "kind": "number",
      "hint": null,
      "default": 52,
      "unit": "ft",
      "min": 1,
      "max": null
    },
    {
      "id": "height",
      "label": "Wall height",
      "kind": "number",
      "hint": null,
      "default": 8,
      "unit": "ft",
      "min": 4,
      "max": null
    },
    {
      "id": "doors",
      "label": "Doors",
      "kind": "number",
      "hint": null,
      "default": 2,
      "unit": null,
      "min": 0,
      "max": null
    },
    {
      "id": "windows",
      "label": "Windows",
      "kind": "number",
      "hint": null,
      "default": 3,
      "unit": null,
      "min": 0,
      "max": null
    },
    {
      "id": "coats",
      "label": "Coats",
      "kind": "number",
      "hint": null,
      "default": 2,
      "unit": null,
      "min": 1,
      "max": 4
    },
    {
      "id": "coverage",
      "label": "Coverage per gallon",
      "kind": "number",
      "hint": null,
      "default": 350,
      "unit": "sq ft",
      "min": 100,
      "max": null
    },
    {
      "id": "price",
      "label": "Price per gallon",
      "kind": "number",
      "hint": null,
      "default": 42,
      "unit": "$",
      "min": 0,
      "max": null
    }
  ],
  "outputs": [
    {
      "id": "buy",
      "label": "Gallons to buy",
      "format": "number",
      "hint": null,
      "primary": true
    },
    {
      "id": "gallons",
      "label": "Gallons required",
      "format": "decimal",
      "hint": null,
      "primary": false
    },
    {
      "id": "cost",
      "label": "Paint cost",
      "format": "currency",
      "hint": null,
      "primary": false
    },
    {
      "id": "net",
      "label": "Paintable area (sq ft)",
      "format": "decimal",
      "hint": null,
      "primary": false
    },
    {
      "id": "gross",
      "label": "Gross wall area (sq ft)",
      "format": "decimal",
      "hint": null,
      "primary": false
    },
    {
      "id": "primer",
      "label": "Primer gallons (1 coat)",
      "format": "decimal",
      "hint": null,
      "primary": false
    }
  ],
  "worked_example": {
    "inputs": [
      "Room perimeter: 52 ft",
      "Wall height: 8 ft",
      "Doors: 2",
      "Windows: 3",
      "Coats: 2",
      "Coverage per gallon: 350 sq ft",
      "Price per gallon: 42 $"
    ],
    "outputs": [
      "Gallons to buy: 2",
      "Gallons required: 1.88",
      "Paint cost: $84",
      "Paintable area (sq ft): 329",
      "Gross wall area (sq ft): 416",
      "Primer gallons (1 coat): 0.94"
    ]
  },
  "how_to": {
    "title": "How to use this",
    "steps": [
      "Enter room perimeter (ft).",
      "Enter wall height (ft).",
      "Enter doors.",
      "Enter windows.",
      "Enter coats.",
      "Enter coverage per gallon (sq ft).",
      "Enter price per gallon ($).",
      "Read your gallons 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": 31,
        "height": 8,
        "doors": 1,
        "windows": 2,
        "coats": 1,
        "coverage": 210,
        "price": 25
      }
    },
    {
      "name": "Typical",
      "description": "Defaults — the most common real-world setup.",
      "values": {
        "perimeter": 52,
        "height": 8,
        "doors": 2,
        "windows": 3,
        "coats": 2,
        "coverage": 350,
        "price": 42
      }
    },
    {
      "name": "Ambitious",
      "description": "Higher-end numbers — what if things really pop?",
      "values": {
        "perimeter": 83,
        "height": 8,
        "doors": 3,
        "windows": 5,
        "coats": 3,
        "coverage": 560,
        "price": 67
      }
    }
  ],
  "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 paint gallons & cost calculator work?",
      "a": "One gallon covers roughly 350 sq ft on smooth drywall and closer to 250 sq ft on textured or porous surfaces. Two coats is the norm over a color change. The underlying maths is: Gallons = (wall area − openings) × coats ÷ coverage."
    },
    {
      "q": "What do I need to enter?",
      "a": "7 values: room perimeter, wall height, doors, windows, coats, coverage per gallon, and price per gallon. 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 gallons 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/drywall-calculator",
    "https://www.revenuelab.fyi/toolbox/wallpaper-calculator"
  ],
  "license": "CC-BY-4.0",
  "citation": "RevenueLab — Paint Coverage Calculator (https://www.revenuelab.fyi/toolbox/paint-coverage)"
}