I think you lost me at the first sentence. You wrote, "It's 21k working only 40hrs." As this was in response to my minimum wage $15 an hour comment, then I'm guessing you are responding, saying you only make 21k at that? I am not a tax professional and not familiar enough to even hazard a guess at what your rate might be earning $15 an hour for 2,000 hours in a year, but keeping only 21k out of a 30k earnings is a 30% rate which seems really high to me earning so little.