You can embed the Mortgage Calculator on your website as a widget, or an iframe. The widget is the preferred implementation method, as it embeds the JavaScript widget directly on your web page, providing the best user experience.
Using the iframe implementation is a bit simpler, and eliminates the potential for your existing website code to interfere with the widget; however, user experience may be sub-optimal due to the iframe sizing and scrolling, and may not work properly for users who have disabled third-party cookies in their browser security settings.