Kinda depends where I am. I think a lot of kids at my martial arts studio can tell at a non-verbal level I'm not really a "chick." They're told to answer to me "yes ma'am" so they do, but I can kinda tell a lot of them have to remind themselves to call me by female pronouns and on a casual level, a lot of the boys, outside of class include me as "one of the guys" when they go our of their way separate themselves from girls.
A lot of times I think I pass until I talk, and sometimes it's just hit of miss. I notice I pass a lot better when vacationing in Asia, where my sense of clothing and such doesn't push me nearly as much into the "androgynous" area... kinda makes me wanna spend a lot more kind back home. Koreans also seem to have a much more amused reaction when they're confused by my gender like "oh, I thought you were a boy, haha well you obviously like guy stuff so let us direct you to the boy's section here." I totally pass for a guy in Japan for some reason, but I think it may also be the culture is just so polite no ones really says anything. Plus I refer to myself in the masculine if I introduce myself so that probably helps. Americans just seem to get flustered and I have no idea what the thought process is when they tiptoe around me... I sometimes feel like they want to be polite and don't want to get things wrong, and others like they just have no idea what to do with me. It's all kinds of awkward...
Then there are places like the game store, where I figured I was perceived as kind gender neutral. I'm always in men's clothing there, but people know I'm at least biologically female. Then recently one of the guys who's a good friend and knows I'm trans said "you know it's amazing to watch how the guys at the store flock around you when you're there" "What do you mean?" "Well, they can sense a 'chicks' in the store and they just follow you around" "What?! Who, I mean, all the chicks at the store are girly-girls, why'd they even think of me like a chick' ' I dunno, probably, cuz all the girls who come to the store are another guy's girlfriend and they're thinking oh man, that's chick's totally into the Imperial Guard just like me, and likes to talk about firearms just like me, and geeks out about nerd stuff just like me!' 'WTF! doesn't the fact that I only ever role-play male characters give people a hint?' 'Probably not...' T-T