Embed our calculators

Any calculator here can go on your own site with a single iframe. It is free, needs no API key or account, and there is nothing to sign. We ask for one thing in return: keep the credit link that sits underneath the frame. That link is the whole reason we can afford to give the calculators away, and it is the only payment we take.

Reasonable uses: a 3PL putting a dimensional weight calculator on its pricing page, an accountant embedding the landed cost tool in a client guide, a seller community adding the FBA calculator to a resources page, a course or textbook linking a worked example.

The snippet

Both lines matter. The <iframe> renders the calculator; the <p> underneath it is the credit, and it has to live in your page rather than inside the frame.

<iframe
  src="https://shipmargin.net/embed/dimensional-weight-calculator/"
  title="Dimensional weight calculator"
  width="100%"
  height="760"
  style="border:1px solid #dde3ec;border-radius:12px"
  loading="lazy"
></iframe>
<p style="font:14px/1.5 system-ui;margin:.5rem 0 0">
  <a href="https://shipmargin.net/dimensional-weight-calculator/">Dimensional weight calculator</a>
  by <a href="https://shipmargin.net/">ShipMargin</a>
</p>

Swap the slug for whichever calculator you want. Height varies by tool — 640 pixels suits the simple ones, 900 the Amazon FBA calculator. Set loading="lazy" so it does not slow your own page down.

Why the credit line is separate from the frame

An iframe is a second document. Everything inside it — including the small credit strip we render at the bottom of every embed — belongs to shipmargin.net, not to the page it is sitting on. A search engine reads those as our own internal links and attributes nothing to you or to us. So a credit that lives only inside the frame is invisible where it counts, which is exactly the mistake this page used to make: it shipped the iframe on its own and told you attribution was optional.

The two-line snippet fixes that. The paragraph is ordinary HTML in your document, so it reads as a normal link on a normal page — it tells your readers where the numbers came from, and it tells everyone else that the calculator is maintained by someone who publishes their sources. Please do not add rel="nofollow"; if you would rather not link at all, use the calculator on our site instead and take nothing.

Pre-filling the inputs

Every calculator encodes its state in the query string, so you can ship an embed that already has your typical values in it. Open the tool, set it up how you want, press Copy shareable link, then insert /embed in front of the slug and use that as the iframe source.

A 3PL that mostly ships 40 × 30 × 20 cm cartons on DHL can embed exactly that, so the reader sees their own scenario rather than a generic default.

What you are embedding

• No third-party scripts, no cookies, no tracking pixels, no advertising.
• Calculations run in the visitor's browser. Nothing they type reaches us or you.
• Light and dark themes follow the visitor's own system preference.
• Between 34 and 70 KB of JavaScript depending on the calculator, served from a global edge network.

One caveat worth knowing. Browsers block downloads started inside a sandboxed iframe, so the CSV export button may do nothing in an embed depending on the sandbox attribute you use; copy the shareable link instead. The frame also carries its own small credit strip, but treat that as a courtesy to your readers rather than as the attribution — the credit that counts is the paragraph in your own HTML, for the reason above.

Data feeds

If you would rather have the underlying data than an iframe — divisor tables, de minimis thresholds, marketplace fee schedules with their effective dates and sources — get in touch. We are happy to expose it as JSON for anything that will cite it properly, and we would rather people build on correct data than re-key a table that goes stale.

Terms

Do not modify the calculator, present its output as your own authoritative rates, or strip the source citations — those are the point. Otherwise, help yourself. Questions via the contact page.