Currency converter in WordPress helps your users to easily do currency conversion on your WordPress site. First thing you need to do is install and activate the WP Currency Converter plugin. Upon activation, go to Settings > WP Currency Converter to add or remove currencies from the converter. This plugin comes with a widget which you can add in your WordPress sidebar or any other widget-ready area. Simply add default currencies using the standard three letter code and click on save to store your settings. You can also show currency converter inside posts and pages using the shortcode. Feel free to change title and and pre-tool paragraph text to anything you want.
If you want to see the inside posts and pages using the shortcode, you can check out here.