Wall sheathing calculator
This wall sheathing calculator estimates how many four-by-eight sheathing sheets you need to cover exterior wall area once you know the gross wall surface, optional door and window openings, and a waste allowance for cuts.
Run — free
It subtracts openings from the gross wall area to form a net sheathing area, divides by the face of one sheet (default four by eight, thirty-two square feet when you work in feet), multiplies by one plus the waste percent, and rounds up to a whole sheet count so your lumberyard list is not short after gable cuts and odd returns. A common check uses one thousand two hundred eighty square feet of wall, one hundred twenty square feet of openings, default four-by-eight sheets, and ten percent waste, which yields a clear integer sheet total instead of a rough pallet guess. The engine is pure deterministic arithmetic with no network calls, no sampling, and no date-dependent shortcuts. Use it free in the browser for DIY framing lists and contractor take-offs, or call the API at $0.002 per successful request when you need reproducible sheet counts in estimating software, spreadsheets, or CI fixtures.
How to use it
Enter your values in the form above. The tool checks them before calculating and shows the result on the same page.
Check your inputs
Use the labels and units shown next to each field. If something is missing or outside the allowed range, the page points to the field to fix.
Use it again or automate it
Use the browser tool for individual checks and the API when you need the same capability in an automated workflow.
What you can do with it
Get an answer now
Enter one set of values and see the result without building a spreadsheet or script.
Compare scenarios
Change one value at a time and rerun the calculation to understand what affects the result.
Automate repeated work
Use the API when the same calculation needs to run inside your product or workflow.
FAQ
How do I use this capability?
Complete the fields above and run it on this page. The form highlights anything that needs attention.
For developers — API access
Everything on this page is available programmatically. This section is for teams who want to wire it into their own systems; everyone else can just use the tool above.
API endpoint
Prefer to automate it? One authenticated POST creates the task; the result comes back by webhook or a signed link. The same capability also runs here on the web, by email and from Telegram — and soon from our app too.
Call it from your stack
curl -X POST https://api.kit.forhosting.com/home/wall-sheathing-sheets \
-H "Authorization: Bearer $KIT_KEY" \
-H "Content-Type: application/json" \
-d '{"wall_area":1280}'const res = await fetch("https://api.kit.forhosting.com/home/wall-sheathing-sheets", {
method: "POST",
headers: {
"Authorization": `Bearer ${process.env.KIT_KEY}`,
"Content-Type": "application/json"
},
body: JSON.stringify({
"wall_area": 1280
})
});
const { task_id } = await res.json();import os, requests
res = requests.post(
"https://api.kit.forhosting.com/home/wall-sheathing-sheets",
headers={"Authorization": f"Bearer {os.environ['KIT_KEY']}"},
json={
"wall_area": 1280
},
)
task_id = res.json()["task_id"]<?php
$res = file_get_contents("https://api.kit.forhosting.com/home/wall-sheathing-sheets", false, stream_context_create([
"http" => [
"method" => "POST",
"header" => "Authorization: Bearer " . getenv("KIT_KEY") . "\r\nContent-Type: application/json",
"content" => '{"wall_area":1280}',
],
]));
$task = json_decode($res, true);body := bytes.NewBufferString(`{"wall_area":1280}`)
req, _ := http.NewRequest("POST", "https://api.kit.forhosting.com/home/wall-sheathing-sheets", body)
req.Header.Set("Authorization", "Bearer "+os.Getenv("KIT_KEY"))
req.Header.Set("Content-Type", "application/json")
res, _ := http.DefaultClient.Do(req)Example request
{
"wall_area": 1280
}Example response
{
"task_id": "tsk_a1b2c3d4e5f6a1b2c3d4e5f6",
"type": "home.wall_sheathing_sheets",
"status": "queued",
"_links": {
"result": "/tasks/tsk_…/result"
}
}The API is asynchronous: the call returns a task_id immediately and the result arrives by webhook. Polling is capped at 1 req/s per task.
Pricing
Published price — no tokens, no invented credits. A failed task is never charged.
Errors
| HTTP | Code | Meaning |
|---|---|---|
401 | unauthorized | Missing or invalid API key. |
402 | insufficient_balance | Your balance doesn't cover the task price. |
404 | unknown_type | That task type doesn't exist. |
429 | rate_limited | Too many requests. Use the webhook instead of polling. |