Free website component
Embed a working calculator on your website
Choose a calculator, copy one script tag and paste it into any page that accepts custom HTML. The free embed is responsive, updates when Kalcify updates the tool and includes a visible “Powered by Kalcify” source link.
No account, API key or npm package is required for the attributed free tier. Visitor inputs stay inside the embedded browser frame and are not sent to Kalcify.
Interactive generator
Build the script tag
<script src="https://kalcify.org/embed/v1.js"
data-tool="salary-calculator-uk"
data-title="Salary Calculator UK 2026/27"
data-height="720"></script>Live preview
The same free embed your visitors will see
Previewing Salary Calculator UK 2026/27. The loader starts at your chosen height, then listens only for a height message from its own Kalcify frame and resizes automatically.
Installation
Paste it into HTML, WordPress, Webflow or a CMS block
Plain HTML
Paste the script where the calculator should appear in the page body.
WordPress
Use a Custom HTML block. Do not paste the tag into a paragraph or code-display block.
Webflow and other CMSs
Use an Embed or Custom Code element that permits third-party script tags.
Some hosted site builders remove scripts from free plans. In that case you need a plan that permits custom JavaScript; an iframe pasted directly will not receive automatic height updates and is not the supported integration.
Stable v1 contract
What each attribute does
| Attribute | Required | Purpose |
|---|---|---|
| data-tool | Yes | Canonical calculator slug selected above. |
| data-title | Recommended | Accessible title assigned to the generated iframe. |
| data-height | No | Initial pixels before automatic resizing; default 640. |
| data-license | Paid tier only | Domain-bound token that removes the attribution bar. |
The path is versioned. Compatible fixes can ship to /embed/v1.js; a breaking API change would use a new version instead of silently changing this tag.
Privacy and attribution
The free tier has one visible condition
Keep the source link visible
The free frame includes a fixed “Powered by Kalcify” bar linking to the canonical calculator. Do not cover, crop or intercept it. The link identifies the source and funds continued free maintenance through legitimate attribution.
Inputs stay client-side
The tool UI and calculations run in the visitor's browser. Embed mode loads no Kalcify advertising or analytics, and the height message contains only an integer. Your own page and consent obligations still apply around the frame.
Troubleshooting
If the calculator does not appear
- 1. Confirm the published page still contains the script tag rather than escaped text.
- 2. Check that
data-toolexactly matches the generated lowercase slug. - 3. Allow
https://kalcify.orgin the page's Content Security Policy for scripts and frames. - 4. Disable script-delay optimisation for
/embed/v1.jsif it rewrites third-party scripts. - 5. Email [email protected] with the public page URL and browser error.
Need the calculator without Kalcify branding?
A domain license removes only the attribution bar. The calculation, responsive loader, client-side privacy model and automatic updates are the same.
Compare the free and white-label tiers →