Free CardFeeCalc calculator widgets for your website
Paste a lightweight script on your blog, docs, or checkout help page. The widget loads in a sandboxed iframe, auto-resizes, and shows a small Powered by CardFeeCalc link on your page (required for the free tier).
Card fee calculator
Single-processor fee estimate with a processor picker (US and UK published rates).
Script embed (recommended)
<script src="https://cardfeecalc.com/embed.js" data-calc="fees" async data-processor="stripe"></script>
Iframe fallback
<iframe src="https://cardfeecalc.com/embed/fees?processor=stripe&theme=light" title="CardFeeCalc fees calculator" style="width:100%;max-width:800px;border:0;min-height:320px" loading="lazy"></iframe>
Compare processors
Rank Stripe, Square, PayPal, and other published US rates on one charge.
Script embed (recommended)
<script src="https://cardfeecalc.com/embed.js" data-calc="compare" async></script>
Iframe fallback
<iframe src="https://cardfeecalc.com/embed/compare?theme=light" title="CardFeeCalc compare calculator" style="width:100%;max-width:800px;border:0;min-height:320px" loading="lazy"></iframe>
Surcharge calculator
Credit-card surcharge estimate with Visa 3% cap, optional state rules, and conservative vs gross-up modes.
Script embed (recommended)
<script src="https://cardfeecalc.com/embed.js" data-calc="surcharge" async></script>
Iframe fallback
<iframe src="https://cardfeecalc.com/embed/surcharge?theme=light" title="CardFeeCalc surcharge calculator" style="width:100%;max-width:800px;border:0;min-height:320px" loading="lazy"></iframe>
Need this as an API?
We're considering a paid JSON API for card fee and surcharge calculations. Leave your email if you'd like a heads-up when it's ready — no commitment.
Free embed terms
- Free to embed on commercial and personal sites.
- Keep the visible Powered by CardFeeCalc link (script embed adds it automatically).
- Figures are estimates from published rates; not legal, tax, or processor advice.
- No warranty; use at your own risk. We may change or discontinue widgets with notice on this page.