From Thinkingbytes Technology:
Professional tax preparers and accountants will probably appreciate this tool more than the average person, but Tax Estimator 2000 is an excellent tool for estimating whether a person can expect to receive an IRS refund and how much! These are just some items to note: The database uses formulas found in the IRS TAX RATE SCHEDULES so actual dollar amounts may vary slightly from the IRS TAX TABLES. The database calculates up to the 31% tax bracket. After that bracket, Tax Estimator probably would not provide accurate estimates since items like Capital Gains tax rates, and AMT generally skews the numbers. This tool should only be used to ESTIMATE a refund or balance due. Do not consider it a quote. Because of the number of conditional expressions and calculations, certain values may take a while to calculate. If a number looks wrong, try refreshing the calculation by tapping the value once every couple of seconds until it stabalizes. Tabs 4 & 5 apply primarily to professional tax preparers. Tab 4 ties a completed estimate to an address book contact. Tab 5 records when an estimate was provided, whether the preparer completed an actual return, and any additional notes.