Informal:
* "Ṣe o" (pronounced "she o") - This is a very common and casual way to tell someone to calm down. It literally means "Do you?" but in this context, it's more like "Chill out" or "Take it easy."
* "Má binu" (pronounced "ma bee-noo") - This literally means "Don't be angry," but it can also be used to tell someone to calm down.
Formal:
* "Duro déédéé" (pronounced "doo-roh de-deh-deh") - This literally means "Stop being restless," and it's a more formal way to tell someone to calm down.
* "Máa gbé ara rẹ̀ mó" (pronounced "maa gbeh a-ra reh mo") - This literally means "Don't be upset," and it's a more respectful way to tell someone to calm down.
The best phrase to use will depend on your relationship with the person you are speaking to and the situation.