happytails.ai

Siding calculator

Open Siding calculator on Happytails.ai. This view has the same page content and links, with explicit tool capabilities. Read the processing notes before using a tool.

Tool capabilities

{
  "id": "siding-calculator",
  "category": "calculators",
  "built": true,
  "requirements": "Up to 300 rows and 100,000 characters, widths up to 1,000 m, heights up to 100 m and counts from 1 to 1,000, exposure up to 600 mm (23.6 in), board length up to 10 m, carton coverage up to 100 m² and waste from 0 to 50%. Calculated on your device; download a JSON report, a results CSV and a wall surfaces CSV.",
  "implementation": {
    "fields": [
      {
        "key": "lengthUnit",
        "label": "Wall dimension unit",
        "value": "ft",
        "type": "select",
        "values": [
          "ft",
          "in",
          "yd",
          "m",
          "cm",
          "mm"
        ]
      },
      {
        "key": "product",
        "label": "Siding sold as",
        "value": "Lap boards",
        "type": "select",
        "values": [
          "Lap boards",
          "Cartons or panels by area"
        ]
      },
      {
        "key": "exposureUnit",
        "label": "Exposure unit",
        "value": "in",
        "type": "select",
        "values": [
          "in",
          "mm",
          "cm"
        ],
        "showWhen": {
          "product": [
            "Lap boards"
          ]
        }
      },
      {
        "key": "exposure",
        "label": "Exposure (reveal) per course",
        "value": 7,
        "type": "number",
        "min": 0,
        "step": "any",
        "help": "Visible height of each course after the overlap, such as 7 in for an 8.25 in plank. Not the full board width.",
        "showWhen": {
          "product": [
            "Lap boards"
          ]
        }
      },
      {
        "key": "boardLength",
        "label": "Board length",
        "value": 12,
        "type": "number",
        "min": 0,
        "step": "any",
        "showWhen": {
          "product": [
            "Lap boards"
          ]
        }
      },
      {
        "key": "coverageUnit",
        "label": "Coverage unit",
        "value": "ft²",
        "type": "select",
        "values": [
          "ft²",
          "m²"
        ],
        "showWhen": {
          "product": [
            "Cartons or panels by area"
          ]
        }
      },
      {
        "key": "coverage",
        "label": "Coverage per carton or panel",
        "value": 200,
        "type": "number",
        "min": 0,
        "step": "any",
        "help": "Net wall coverage printed on the carton, or the face area of one panel, such as 32 ft² for a 4 × 8 ft sheet.",
        "showWhen": {
          "product": [
            "Cartons or panels by area"
          ]
        }
      },
      {
        "key": "waste",
        "label": "Waste allowance (%)",
        "value": 10,
        "type": "number",
        "min": 0,
        "max": 50,
        "step": "any",
        "help": "Extra for cuts, laps at board ends and damage. Enter 0 for none."
      }
    ],
    "registrationFamily": "roof-and-cladding",
    "input": true,
    "live": false,
    "presentation": "metrics",
    "inputMaxLength": 100000,
    "inputErrorCode": "ROOF_AND_CLADDING_TOO_LONG",
    "note": "Calculated on your device for up to 300 rows and 100,000 characters, walls up to 1,000 m long and 100 m high. Exposure and coverage come from your siding product.",
    "experience": {
      "automatic": false,
      "single": false,
      "inputMaxLength": 100000,
      "inputMode": "text",
      "label": "Walls, gables and openings",
      "placeholder": "wall, Front, 40, 9",
      "help": "One row per line: type (wall, gable or opening), name, width, height and an optional count. Up to 100,000 characters. Review the settings before running.",
      "helpParts": [
        "One row per line: type (wall, gable or opening), name, width, height and an optional count.",
        "Up to 100,000 characters.",
        "Review the settings before running."
      ],
      "action": null
    },
    "mode": "explicit",
    "interactive": false
  },
  "execution": "Browser interface",
  "api": null,
  "browser_agent": {
    "supported": true,
    "name": "run_current_tool",
    "discovery": "WebMCP on the human page in a supporting browser",
    "verification": "See audit/API-AUDIT.md; availability is not verification"
  }
}

Page guide

List your walls, gables, windows and doors to get the net siding area, squares and the number of lap boards or cartons, plus starter and trim lengths.

How to use Siding calculator
  1. Enter one row per line: wall, gable or opening, a name, the width and height, and an optional count.
  2. Choose the wall dimension unit and whether the siding is sold as lap boards or by carton area.
  3. Enter the exposure and board length, or the coverage per carton, and the waste allowance.
  4. Review the net area, squares and pieces, then download the report and CSV files.

Useful next steps

Paint calculatorSquare footageBrick calculator

Net wall area

Walls are rectangles, gables are triangles of base × height ÷ 2, and windows and doors are subtracted. Fine Homebuilding uses the same break-down into rectangles and triangles for roofs (Mike Guertin, How to Estimate Materials for Roofing Projects, checked 16 October 2026). In the example, 1,420 ft² of walls and gables less 160.5 ft² of openings leaves 1,259.5 ft².

Boards from exposure

A lap board covers only its exposure, the visible reveal after the overlap, times its length. An 8.25 in plank laid with a 7 in exposure in 12 ft lengths covers 7 ft², so 1,259.5 ft² plus 10% waste needs 198 boards. For vinyl cartons or sheet panels, enter the net coverage per carton or the face area of one panel instead.

Squares and trim

Siding is often priced by the square, 100 ft² (Wikipedia, Square (unit), checked 16 October 2026). The starter strip length is the total width of the wall rows, opening trim is the perimeter of each opening, and gable trim is both sloped edges of each gable from the Pythagorean theorem (OpenStax Precalculus 2e, 5.4, checked 16 October 2026).

Limits

Corner posts, soffits, fascia and house wrap are not included, and exposure and coverage are product-specific, so check the product literature. Unit conversions use NIST SP 811.