So, "It's clear to me" means "I have understood what it means" while "I'm clear on that" means "I have made my points clear (so you should have understood)".

And "I'm clear about that" is ambiguous in meaning for it can mean both "I have made clear what you mean" and "I have made clear what I mean". So I would be recommended to avoid using it.

Am I clear on that? And has it been clear to me?


I don't think there's a scintilla of difference between "It's clear to me." and "I'm clear on that."

"Are we clear" is more like "do we understand each other."