At the risk of infuriating you all and alienating the posters around this place that I admire so much (I've been lurking for over a year now), it looks like I'll have a net -47% income tax and actually "earn" money by filing my return.
I'm an indebted $0.00 earning med student, my wife earned about $12k working part-time while also being a full-time mom (got 1 kid). About $900 have been withheld from my wife's paychecks. That calculator estimates that we'll receive a refund of a little over 5k, which is about what we got last year.
Not sure how I feel about that. Personally we're very grateful, but I'm also bothered because I know they'd be giving me money even if I wasn't on a path to success. Over the course of my career we will pay back many times what we received. Too many people will never pay back anything.