With Coupon Affiliates, you can enable multi-currency support and easily set conversion rates for all your store currencies.
This will then automatically convert the order totals, total stats, and commission earned, in the affiliate dashboard to your base store currency, no matter which currency each of the orders were made in.
Here’s an example of the settings.

To get started, simply enable multi-currency settings under the “General” tab of the plugin settings page. A new tab will the appear labeled “currencies” to customise your currencies and conversion rates.