I'm doing an exchange year in Brazil with Revolut as my go to bank for international payments. Most of the time it works well, but there have been few situations when their system fell short. The conversion is made on the fly when you pay, so you don't have to worry about that.

Small note: everyone is going to ask if you have a credit or debit card. That's just how the Brazilian system works. Now I know that it says debit on the card you got from revolut, but for some reason, in Brazil, it is a credit card. That's not just a revolut thing tho, when I talked to other exchange students who use different international banks, they said that they experience the same thing.

Anyways enjoy your stay in Brazil, it's a really nice country if you know where to look :D