How do you say you are fine in spanish?

Estoy Bien

Estoy mas o menos


or


Estoy asi-asi
(Some people say that this is used more for when a person is ok, and does not want you to help them, they will say asi, asi, like saying, "It's okay, I can do it myself" But it does not indicate that they are ok, it is not used in a proper sentence, mostly for a situation where they do not need help and are saying not to help as an indicator that they are ok to do it themselves.)