Free Amazon calculator widgets — embed them on your site
One copy-paste iframe snippet adds a live, always-current 2026 Amazon seller calculator to your blog post, course page or tool directory. Three widgets are available — seller fees, FBA reimbursements and Amazon's currency conversion fee. Free for any site that keeps the attribution link — no signup, no API key.
1 · Amazon seller fees calculator
Referral fee by category plus the 2026 FBA fulfilment fee, profit and ROI — the full per-unit fee breakdown sellers use before pricing a product.
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Copy the whole block — the iframe and the credit line under it. The visible link outside the iframe is what credits Marginely on your page (links inside an iframe don't count as an attribution link), and it is the one condition of use.
2 · Amazon FBA reimbursement calculator
Two inputs — annual revenue and how many years back you can still claim — and the widget shows the reimbursement range Amazon is likely holding, what its automatic reimbursements already cover, and what is probably still unclaimed.
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3 · Amazon currency converter (ACCS) fee calculator
What Amazon's own currency conversion costs a cross-border seller each year, and what the same payouts would cost through a multi-currency account instead.
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Options
| Option | Applies to | Values | Notes |
|---|---|---|---|
?embed=1 | all three | required | Turns the page into the widget view: no header, hero, ads, affiliate blocks or footer — inputs, results and the source bar only. |
height | all three | Seller fees 760 · FBA reimbursement 600 · Currency converter 530 | Starting points for desktop — the widgets themselves render 491px, 589px and 518px tall at 1000px wide, and taller on narrow screens (957px, 1055px, 1017px at 380px). Use the auto-height script below to remove the guesswork. |
width | all three | 100% recommended | Fully responsive down to 320px; the two panels stack on narrow widths. |
&cat=… | Seller fees | e.g. &cat=clothing | Pre-selects a category, same values as on the calculator page. |
| Source bar | all three | always on | The bottom "Powered by marginely.com" bar with the last-reviewed date cannot be disabled — it is how readers know the rates' vintage. |
Auto-height (optional)
Each embed posts its rendered height to the parent page. Add this once and every Marginely iframe on the page resizes itself — no scrollbars:
What embedders usually ask
Does the widget cost anything?
No — every calculator widget is completely free, for commercial and non-commercial sites alike. The only condition is keeping the visible credit link under the iframe.
Do I need an account or API key?
No signup, no key, no registration. Copy the snippet, paste it, done.
Can I embed more than one calculator on the same page?
Yes. Each widget is an independent iframe, so a single post can carry the fee calculator and the reimbursement calculator side by side. The auto-height script above matches each message to the iframe it came from, so the two never fight over one height.
Does it collect data from my visitors?
Calculator inputs are processed entirely in the visitor's browser and are never transmitted or stored. The embed loads our standard aggregate analytics (page counts only); ads and affiliate blocks that appear on the full pages are removed in embed mode.
What happens when Amazon changes its fees?
Nothing on your side — the iframe always serves the live calculator, so rate updates appear automatically. The bar at the bottom of the widget shows the last-reviewed date.
Which browsers are supported?
All current versions of Chrome, Edge, Safari and Firefox, on desktop and mobile down to 320px wide. JavaScript must be enabled — there is no static fallback.
Terms of use
- Keep the credit link. The snippet's visible link to marginely.com must stay on the page, unmodified — no
nofollow, no hiding. That's the whole price. - Don't misrepresent it. You may not present the calculator as your own product or charge for access to it.
- Rates update on our schedule. The embed always serves the live calculator with Amazon's current published US fees; the bottom bar shows the last-reviewed date. No action needed on your side when fees change.
- No warranty. Figures are estimates from Amazon's published schedules, not financial advice. We may change or discontinue the embed with notice on this page.
Questions or a calculator you'd like embeddable next? Tell us via the about page.