Formal/Literal:
* O lar é onde está o coração. (This is the most literal translation.)
Informal/More poetic:
* Onde estiver o coração, aí está o lar. (This is a more poetic way to say it, and it's more commonly used in everyday speech.)
Idiomatic:
* A casa é onde a gente se sente bem. (This is more of a direct translation of the feeling behind the phrase, meaning "Home is where you feel good.")
It's important to note that these are just a few examples, and the best way to say it will depend on the context and your personal preference.