lookup · lookup
KDP cover size and spine width calculator online
Full cover size, spine width, safe areas, barcode box, gutter and margins for an Amazon KDP paperback, with an optional PDF cover guide; 20 free runs a day, then 1 credit per run, up to 10 seconds per run.
result
Press Run. The result lands here, made by the real tool.
1 credit · ≤10 s · no login · 20 free/day
Keys are stored in this browser only. A key lets you buy credits and keep going after the free runs.
How it works
- Paste your input or edit the example that is already filled in.
- Press Run. The tool executes on our server and returns the real result, with its size and time.
- Check the result below the form, then download it or copy it.
Limits
Each run is capped at 10 seconds. 20 free runs a day per visitor across all mint tools, no login. After that a run costs 1 credit; credits are bought once and attach to an API key.
Privacy
Your input is processed for the request and discarded afterwards. It is not kept and not used for anything else. Usage records keep only time, tool, status, duration and a salted hash of the IP address.
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Call it from code
curl -sS -X POST 'https://data.voiddo.com/v1/kdp_spine_calc' \
-H 'Content-Type: application/json' \
-d '{"trim":"6x9","pages":120,"paper":"white"}'20 calls a day need no key. Beyond that: one-time credit packs, $5 for 500 credits, $9 for 1,000 credits, $29 for 4,000 credits. Get credits · llms.txt · OpenAPI.
Questions
Is this tool free?
Yes, 20 runs a day without an account. After that each run costs 1 credit.
Are my files stored?
No. The input is processed for the request and discarded afterwards.
Can I call it from my own code?
Yes. The same engine is available as an API at data.voiddo.com; the curl example on this page shows the request.