Technical how-to
You don't need a developer, a plugin, or any code knowledge to add a widget to a WordPress site — the built-in editor already has everything needed.
See it on a real page
Try the live calculator embedded exactly as your customers would see it.
View the demo →In the WordPress block editor, add a “Custom HTML” block anywhere on the page or post where you want the calculator to appear, then paste the provided embed snippet directly into it.
Use the page preview (not just the editor view) to confirm the calculator displays and functions as expected — some themes apply styling that can affect how embedded widgets appear, which preview mode reveals immediately.
If nothing appears, double-check the snippet was pasted into a genuine “Custom HTML” block rather than a regular text block, which can strip out the necessary code entirely.
Older “Classic Editor” setups usually support a similar HTML/text widget option — the same embed snippet works there too, just added through a different interface.
The widget is designed to load lightly and shouldn't meaningfully affect page speed on a typical WordPress site.