{
  "slug": "how-much-paint-do-i-need",
  "title": "How Much Paint Do I Need for a Room?",
  "heading": "How Much Paint Do I Need for a Room?",
  "category": "other",
  "url": "https://www.revenuelab.fyi/toolbox/how-much-paint-do-i-need",
  "summary": "A 12x12 room with 8-ft ceilings and two coats needs about 2 gallons of paint after subtracting doors and windows.",
  "description": "Paint coverage is calculated from wall surface area, minus openings like doors and windows, divided by the coverage rate printed on the can (typically 350-400 sq ft per gallon per coat). This tool computes wall area from room dimensions, subtracts a standard allowance for doors and windows, and multiplies by your number of coats to tell you exactly how many gallons or quarts to buy.",
  "formula": "Wall Area = Perimeter × Height − Openings. Gallons = (Wall Area × Coats) ÷ Coverage per Gallon.",
  "dateModified": "2026-09-06",
  "run_url": "https://www.revenuelab.fyi/api/public/calc?tool=how-much-paint-do-i-need",
  "inputs": [
    {
      "id": "length",
      "label": "Room length",
      "kind": "number",
      "hint": null,
      "default": 12,
      "unit": "ft",
      "min": 1,
      "max": null
    },
    {
      "id": "width",
      "label": "Room width",
      "kind": "number",
      "hint": null,
      "default": 12,
      "unit": "ft",
      "min": 1,
      "max": null
    },
    {
      "id": "height",
      "label": "Ceiling height",
      "kind": "number",
      "hint": null,
      "default": 8,
      "unit": "ft",
      "min": 6,
      "max": null
    },
    {
      "id": "doors",
      "label": "Number of doors",
      "kind": "number",
      "hint": null,
      "default": 1,
      "unit": null,
      "min": 0,
      "max": null
    },
    {
      "id": "windows",
      "label": "Number of windows",
      "kind": "number",
      "hint": null,
      "default": 2,
      "unit": null,
      "min": 0,
      "max": null
    },
    {
      "id": "coats",
      "label": "Number of coats",
      "kind": "number",
      "hint": null,
      "default": 2,
      "unit": null,
      "min": 1,
      "max": 4
    },
    {
      "id": "coverage",
      "label": "Coverage per gallon",
      "kind": "number",
      "hint": null,
      "default": 375,
      "unit": "sq ft",
      "min": 200,
      "max": 500
    }
  ],
  "outputs": [
    {
      "id": "gallons",
      "label": "Gallons needed",
      "format": "decimal",
      "hint": null,
      "primary": true
    },
    {
      "id": "quarts",
      "label": "Quarts equivalent",
      "format": "decimal",
      "hint": null,
      "primary": false
    },
    {
      "id": "netArea",
      "label": "Paintable wall area (sq ft)",
      "format": "number",
      "hint": null,
      "primary": false
    }
  ],
  "worked_example": {
    "inputs": [
      "Room length: 12 ft",
      "Room width: 12 ft",
      "Ceiling height: 8 ft",
      "Number of doors: 1",
      "Number of windows: 2",
      "Number of coats: 2",
      "Coverage per gallon: 375 sq ft"
    ],
    "outputs": [
      "Gallons needed: 1.78",
      "Quarts equivalent: 7.1",
      "Paintable wall area (sq ft): 333"
    ]
  },
  "how_to": {
    "title": "How to use this",
    "steps": [
      "Enter room length (ft).",
      "Enter room width (ft).",
      "Enter ceiling height (ft).",
      "Enter number of doors.",
      "Enter number of windows.",
      "Enter number of coats.",
      "Enter coverage per gallon (sq ft).",
      "Read your gallons needed 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": {
        "length": 7.199999999999999,
        "width": 7.199999999999999,
        "height": 8,
        "doors": 1,
        "windows": 1,
        "coats": 1,
        "coverage": 225
      }
    },
    {
      "name": "Typical",
      "description": "Defaults — the most common real-world setup.",
      "values": {
        "length": 12,
        "width": 12,
        "height": 8,
        "doors": 1,
        "windows": 2,
        "coats": 2,
        "coverage": 375
      }
    },
    {
      "name": "Ambitious",
      "description": "Higher-end numbers — what if things really pop?",
      "values": {
        "length": 19.200000000000003,
        "width": 19.200000000000003,
        "height": 8,
        "doors": 2,
        "windows": 3,
        "coats": 3,
        "coverage": 500
      }
    }
  ],
  "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 much paint do I need for a room?",
      "a": "A 12x12 room with 8-foot ceilings, one door, and two windows has about 320 sq ft of paintable wall area; at two coats and 375 sq ft/gallon coverage, that's roughly 1.7 gallons — round up to two gallons."
    },
    {
      "q": "Why subtract for doors and windows?",
      "a": "A standard door opening removes about 21 sq ft and a standard window about 15 sq ft of area you don't need to paint, which can be 10-20% of total wall area in a small room."
    },
    {
      "q": "Do I need two coats?",
      "a": "Two coats is standard for a color change or new drywall. A single coat of the same color as a touch-up may only need one, cutting your gallons roughly in half."
    },
    {
      "q": "Should I buy extra?",
      "a": "Buy about 10% extra for touch-ups later and to account for textured walls, which soak up more paint than the can's stated coverage rate assumes."
    }
  ],
  "related": [
    "https://www.revenuelab.fyi/toolbox/how-much-flooring-do-i-need",
    "https://www.revenuelab.fyi/toolbox/how-many-square-feet-is-my-room"
  ],
  "license": "CC-BY-4.0",
  "citation": "RevenueLab — How Much Paint Do I Need for a Room? (https://www.revenuelab.fyi/toolbox/how-much-paint-do-i-need)"
}