Translation:Es ist egal.
is this really an idiomatic equivalent? 'Es ist egal', for me, would be closer to 'it doesn't matter', and suggests a choice is being proposed - and therefore 'never mind' wouldn'y (scottish :) ) really make sense. The idiomatic 'middle-term' here being 'whatever', which according to my line of thinking would here have as its equivalent 'whichever', and not 'it doesn't matter' (not to be understood in the same way as, 'it doesn't matter - which one-.') I.e. One involves continued participation, albeit reluctant, in some discussion of choice, while the other signals the end of an exchange (by someone who's no longer interested in talking to you). (Apologies if all this seems unnecessarily long-winded.)
There're equivalent idioms in German which might suit the intention better. 'Vergiss es' (Forget about it) and 'Schon gut' (It's alright, sometimes leaning towards 'Let it be, it's alright, I'll do it myself'). 'Es ist egal' might be one of them, like Heck, I dropped your watch - Never mind, I wanted to buy a new one anyway. Here, 'Ist egal' or 'Nicht schlimm' seem appropriate to me.