A couple of months ago I filed the 2012 tax returns. I was expecting a few thousands USD for a refund. Finally, the payment was received in my bank account, and I noticed that the actual refund was about $180 more than my estimates.
Every year I am preparing the returns with a self-prepared spreadsheet, which is verified by the calculations made by Free File Fillable Forms application in the IRS website.
Since the basic application calculation matches my spreadsheet calculation to the dollar, I am concluding that the $180 difference comes from my (mis)understanding of one, or some of the rules (like, which choices I should have made, etc.).
Is there a way to get a detailed calculation of the corrected IRS estimate, for educational purposes?