1
Pick a calculator
Choose from 30+ financial calculators below
2
Copy the code
One click copies the <iframe> snippet
3
Paste anywhere
Works in WordPress, Webflow, Substack, Ghost, and raw HTML
Live Example — Compound Interest Calculator
Here's what an embedded calculator looks like on your site. Fully interactive, mobile-responsive, loads in milliseconds.
All Embeddable Calculators
Click Copy on any card to get the embed code. Visit the calculator page for an interactive size picker.
Frequently Asked Questions
Yes, completely free. No usage limits, no API keys, no account required. The calculators are hosted on our servers and we cover all bandwidth costs.
Attribution is not required, but we appreciate a mention or link back to InterestCal if you find the calculators useful. The embedded widget includes a subtle "Powered by InterestCal" footer that links back naturally.
The iframes use
loading="lazy" so they only load when the user scrolls to them. Our pages are globally cached via CDN and load in under 500 ms. Your Core Web Vitals will not be affected.Yes — just change the
width and height attributes in the iframe tag. We recommend 600–800 px wide and 480–560 px tall for most calculators. You can also use width="100%" for full-width responsive embeds.We maintain stable URLs and embed compatibility. The
?embed=1 parameter is a permanent, supported feature. If we ever make breaking changes, we will provide redirect support.iframes work in WordPress (use the HTML block), Webflow, Wix, Squarespace (Code Block), Ghost, Substack (embed block), Notion, and any standard HTML page. Some platforms like Medium do not support iframes.
Want to embed on your calculator page directly?
Visit any calculator and click the </> Embed this calculator button at the top — it opens an interactive size picker with a live preview.
Open a Calculator →