How to add a calculator to your site
- Pick a calculator below and click Get the code, or use the Add to your website box on any calculator page.
- Copy the code. It has three parts: the calculator frame, a short credit link, and an optional helper script that resizes the frame to fit.
- Paste it where you want the calculator to appear, using your site builder's HTML block (instructions below).
The calculator runs inside a frame from freetools99.com, so it never conflicts with your theme's styles or scripts, and we update it (new tax rates, fixes) without you doing anything.
WordPress
- Block editor (Gutenberg): add a Custom HTML block, paste the code, then Update.
- Classic editor: switch to the Text tab (not Visual) and paste.
- Elementor: drag in an HTML widget and paste the code.
- WordPress.com free plans remove scripts: paste only the
<iframe>and the credit line. The frame keeps its set height (900 px by default; changeheightif needed).
Blogger
Open the post, switch from Compose view to HTML view (the pencil icon at the top left), paste the code where the calculator should go, then switch back and publish. For the sidebar: Layout → Add a Gadget → HTML/JavaScript.
Wix, Squarespace and Google Sites
- Wix: Add → Embed code → Embed HTML, choose Code, paste, and drag the box to size.
- Squarespace: add a Code block and paste. Code blocks need a Business plan or higher.
- Google Sites: Insert → Embed → Embed code, paste, then resize the box.
These builders put embeds in their own frame, so the auto-resize script can't reach it: set the height to fit instead.
Plain HTML
Paste the code anywhere inside <body>. Load the embed.js line once per page even if you embed several calculators. If your site uses a Content Security Policy, allow frame-src https://freetools99.com and script-src https://freetools99.com.