WP Currency Exchange Rates plugin lets you display currency exchange rates on your site.
Rates can be displayed with:
[alg_cer_get_exchange_rate]
and/or [alg_cer_get_saved_exchange_rate]
shortcodes,alg_cer_get_exchange_rate()
and/or alg_cer_get_saved_exchange_rate()
PHP functions.Exchange rates are updated via Fixer.io API. Please note that you will have to get your free API key from Fixer.io.