Most sit-down restaurants print "10% opcional" (10% optional) directly on the receipt.
Despite the word "optional," paying it is the strong social norm — refusing it is unusual and generally reserved for real complaints about service.
Once that 10% is paid, a further cash tip on top is not expected, though rounding up small change is fine.
Bars and casual spots with no printed service charge: round up or leave small change, nothing more formal.
Outside restaurants
Taxi and rideshare drivers in Brazil are not routinely tipped — rounding the fare up is the most common gesture, and plenty of locals pay the exact metered amount. Hotel porters and housekeeping appreciate a small amount (a few reais) but it is far from obligatory.
Example: dinner in Rio or São Paulo
Bill: R$150.00, with "10% serviço" already printed as R$15.00.
Total paid: R$165.00. No further tip needed unless service was exceptional, in which case rounding to R$170-175 is a generous but optional gesture.
Worth knowing: because the service charge is labelled "optional" but socially expected, some restaurants will ask directly whether you want it included when you pay — saying yes is the norm.
Regional differences within Brazil
Rio de Janeiro and São Paulo, the two cities most visitors spend time in, both follow the 10% pattern closely. In smaller towns and along the northeast coast, the printed service charge is less universal, and a simple "obrigado, ficou bom" (thank you, that was good) with the exact bill amount is just as normal as adding anything extra.