Embed
Put the KDP Cover Calculator on your site
Give your readers the same spine-width and full-cover math, embedded right in your blog post, author site, or course. One iframe snippet — free, auto-resizing, and themeable to your brand.
Free forever, no signup
No API key, no account, no rate limit.
Auto-resizing
Posts its height to the parent so there's no inner scrollbar.
Themeable
Light/dark and a custom accent color via URL params.
One snippet
Paste the iframe + 6-line resize script and you're done.
Copy the snippet
Paste this where you want the calculator to appear. The small script lets the iframe resize itself so there’s no inner scrollbar.
Embed this calculator on your site
<iframe src="https://kdpcover.pro/embed/widget?theme=light"
width="100%" height="640" style="border:0; border-radius:12px"
loading="lazy" title="KDP Cover Calculator"></iframe>
<script>window.addEventListener("message",function(e){
if(e.data && e.data.type==="kdpcover:height"){
var f=document.querySelector('iframe[src*="kdpcover.pro/embed/widget"]');
if(f) f.style.height=e.data.height+"px";
}
});</script>The widget keeps a small “Powered by kdpcover.pro” link — please leave it in place (see Terms).
Live preview
This is the real widget, embedded exactly as the snippet would render it.
Customize it
Append query parameters to the iframe src (https://kdpcover.pro/embed/widget):
| Parameter | Values | Effect |
|---|---|---|
| theme | light · dark | Color scheme. Defaults to light. |
| compact | 1 | Condensed layout — hides the copy / share / embed row. Good for narrow sidebars. |
| accent | hex e.g. 2563eb | Override the accent color to match your brand (URL-encode the #). |
| defaultFormat | paperback · hardcover | Which format the widget opens on. Defaults to paperback. |
Example: /embed/widget?theme=dark&compact=1&defaultFormat=hardcover
Common questions
- Does it cost anything?
- No. The embed is free with no signup or usage limit. We monetize through the optional template pack, not the calculator.
- Will it slow down my page?
- The iframe is
loading="lazy"so it only loads when scrolled near. All calculation runs inside the iframe — nothing touches your page’s JavaScript. - Can I remove the attribution?
- Please keep the small “Powered by kdpcover.pro” link — it’s the only thing we ask in exchange for the free widget, per our Terms.
Prefer it on every page automatically? There’s also a Chrome extension. Or just use the full calculator.