Cake tin size converter
This cake tin size converter turns a round pan diameter or a square pan side into the equal-area counterpart so you can swap tins without guessing how much batter will fit.
Run — free
Baking books and recipe cards often list an eight-inch round or a twenty-centimeter square tin; home kitchens rarely stock every size, so cooks need a reliable bridge between shapes. The engine matches pan area with closed-form geometry: round area is pi times radius squared, square area is side squared, so the side that matches a diameter d is d times square root of pi over two, and the diameter that matches a side s is two s over square root of pi. Lengths are reported in both inches and centimeters using the exact 2.54 factor, and the shared area appears in square inches and square centimeters. Small checks include an eight-inch round mapping to a square side of about seven point zero nine inches, and a twenty-centimeter square mapping back to a round diameter of the same area. Everything is pure arithmetic with no network calls, no sampling, and no date-dependent shortcuts. Use it free in the browser while adapting family recipes, or call the API at $0.002 per successful request when recipe software must convert tin sizes without re-implementing the equal-area formulas.
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/cook/cake-tin \
-H "Authorization: Bearer $KIT_KEY" \
-H "Content-Type: application/json" \
-d '{"size":8,"shape":"round"}'const res = await fetch("https://api.kit.forhosting.com/cook/cake-tin", {
method: "POST",
headers: {
"Authorization": `Bearer ${process.env.KIT_KEY}`,
"Content-Type": "application/json"
},
body: JSON.stringify({
"size": 8,
"shape": "round"
})
});
const { task_id } = await res.json();import os, requests
res = requests.post(
"https://api.kit.forhosting.com/cook/cake-tin",
headers={"Authorization": f"Bearer {os.environ['KIT_KEY']}"},
json={
"size": 8,
"shape": "round"
},
)
task_id = res.json()["task_id"]<?php
$res = file_get_contents("https://api.kit.forhosting.com/cook/cake-tin", false, stream_context_create([
"http" => [
"method" => "POST",
"header" => "Authorization: Bearer " . getenv("KIT_KEY") . "\r\nContent-Type: application/json",
"content" => '{"size":8,"shape":"round"}',
],
]));
$task = json_decode($res, true);body := bytes.NewBufferString(`{"size":8,"shape":"round"}`)
req, _ := http.NewRequest("POST", "https://api.kit.forhosting.com/cook/cake-tin", body)
req.Header.Set("Authorization", "Bearer "+os.Getenv("KIT_KEY"))
req.Header.Set("Content-Type", "application/json")
res, _ := http.DefaultClient.Do(req)Example request
{
"size": 8,
"shape": "round"
}Example response
{
"task_id": "tsk_a1b2c3d4e5f6a1b2c3d4e5f6",
"type": "cook.cake_tin",
"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_size | 1000000 |
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. |