Good for you - Tradução em português

Can somebody tell me what does that mean exactly?

If we translate that literally, we get something like "Bom pra você". But, in Portuguese, "bom pra você" is always said in order to be ironic.

I don't think "Good for you", in English, is ironic. In fact, I think it's very polite.

So, my question is: When do I use "good for you" in English? Is it polite/impolite/ironic?

Thank you in advance!