Tile grout calculator
This tile grout calculator estimates how many kilograms of grout you need for a tiled floor or wall once you know the tile size, joint width, tile thickness, and total surface area.
Run — free
It uses a geometric joint-fraction model: each tile sits in a module that includes its share of the joints, the fraction of the surface that is joint is one minus the tile face over that module, and volume equals area times that fraction times thickness. Weight follows by multiplying volume in litres by bulk density, defaulting to a typical cementitious value of 1.6 kilograms per litre. Small checks you can verify by hand include three-hundred millimetre square tiles with three millimetre joints, eight millimetre thickness, and ten square metres of floor, which yields a few kilograms of grout rather than a bag-per-room guess. The engine is pure arithmetic with no network calls, no sampling, and no date-dependent shortcuts. Use it free in the browser for DIY shopping lists and contractor take-offs, or call the API at $0.002 per successful request when you need reproducible estimates 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/tile-grout \
-H "Authorization: Bearer $KIT_KEY" \
-H "Content-Type: application/json" \
-d '{"joint_width":3,"tile_thickness":8,"area":10,"tile_size":300}'const res = await fetch("https://api.kit.forhosting.com/home/tile-grout", {
method: "POST",
headers: {
"Authorization": `Bearer ${process.env.KIT_KEY}`,
"Content-Type": "application/json"
},
body: JSON.stringify({
"joint_width": 3,
"tile_thickness": 8,
"area": 10,
"tile_size": 300
})
});
const { task_id } = await res.json();import os, requests
res = requests.post(
"https://api.kit.forhosting.com/home/tile-grout",
headers={"Authorization": f"Bearer {os.environ['KIT_KEY']}"},
json={
"joint_width": 3,
"tile_thickness": 8,
"area": 10,
"tile_size": 300
},
)
task_id = res.json()["task_id"]<?php
$res = file_get_contents("https://api.kit.forhosting.com/home/tile-grout", false, stream_context_create([
"http" => [
"method" => "POST",
"header" => "Authorization: Bearer " . getenv("KIT_KEY") . "\r\nContent-Type: application/json",
"content" => '{"joint_width":3,"tile_thickness":8,"area":10,"tile_size":300}',
],
]));
$task = json_decode($res, true);body := bytes.NewBufferString(`{"joint_width":3,"tile_thickness":8,"area":10,"tile_size":300}`)
req, _ := http.NewRequest("POST", "https://api.kit.forhosting.com/home/tile-grout", body)
req.Header.Set("Authorization", "Bearer "+os.Getenv("KIT_KEY"))
req.Header.Set("Content-Type", "application/json")
res, _ := http.DefaultClient.Do(req)Example request
{
"joint_width": 3,
"tile_thickness": 8,
"area": 10,
"tile_size": 300
}Example response
{
"task_id": "tsk_a1b2c3d4e5f6a1b2c3d4e5f6",
"type": "home.tile_grout",
"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.
Limits
max_abs | 1000000000 |
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. |