Showing currency exchange rate at FO

[Pez]

Hi. Is there a module that will show Paypal's currency exchange rate in front office?

 

I'm asking because I used to accept multiple currencies, but lately I keep getting the "The totals of the cart item amounts do not match order amounts" Paypal error, which only happens when the customer tries to pay in a non-default currency and apparently the numbers don't round-up properly. I tried various suggestions from old forum posts but nothing worked. So I'm going back to accepting GBP only but I want to display the exchange rate at the front so foreign customers have an idea how much it'll work out in their own currency.

 

Thanks for any help.