How do you say I dont care in French?

Answer 1

I don't care. = Ça m'est bien égal. (It is well equal to me.)

You can also use: Je m'en fiche.

Note: I, personally, have only heard people use "je m'en fiche" when angry/upset.

I believe the first translation "Ça m'est bien égal" is more courteous.

Answer 2

I don't care is 'je m'en fous' or 'je m'en moque' in French. This is quite familiar and you wouldn't say that to your teacher. A more formal version is 'ça m'est égal'.