When implementing tracking on your website its important to first convert you currency to U.S. Dollars  (USD) before entering the value in the pixel if your currency is not already in U.S. Dollars. Since different technologies can be used to serve a website, its largely up to you, the Advertiser, to determine which way works best for you, its also encourage that if you can implement your exchange server-side that you do.

But in the case of performing the exchange client-side, these resources are useful: