Formal:
* Como está? (pronounced: koh-moh eh-stah?) - This is the most formal way to ask how someone is. It's appropriate for situations where you're speaking to someone you don't know well, someone in a position of authority, or in a professional setting.
Informal:
* Como vai? (pronounced: koh-moh vi?) - This is the most common and informal way to ask how someone is. It's appropriate for friends, family, and people you know well.
* Tudo bem? (pronounced: too-doh bem?) - This literally means "everything good?" It's a very informal way to ask how someone is, and is often used as a greeting.
Other options:
* E aí? (pronounced: eh-ee?) - This is a very casual way to say "how are you?" and is used among friends and peers.
* Tudo tranquilo? (pronounced: too-doh tran-kwee-loh?) - This means "everything calm?" It's a slightly more formal version of "Tudo bem?"
It's important to note that the best way to say "how are you" in Brazilian Portuguese depends on the specific situation and your relationship with the person you're talking to.