How would you translate "Was bilden Sie sich ein"?

Question

From german to english.

Answer 1

Literally, it's more or less: "What are you thinking?"
The way it's used it is normallly equivalent to "How dare you?"

Answer 2

That would usually translate as "What do you [formal] think?"
Where "think" has the idea of "imagining" or "guess"
But depending on context "einbilden" can also mean to fancy or to surmise.

E.g.
I habe den ganzen Tag nichts gegessen.
Denn bilde ich mir ein, dass du wohl Hunger hasst.
=
I haven't eaten all day.
Then I think/guess/imagine you must be hungry.

Answer 3

I guess it means, What are you imagening, so I reckon it makes something like:

Who do you think you are?

Answer 4

What are you building /forming ? [for yourself ]