How to Round Out Amounts on U.S. Federal Tax Returns
- 1). Calculate the amount that you are supposed to enter on a particular line without rounding. For example, if you are entering income from taxable interest and you earned $120.30 from Bank A and $234.40 from Bank B, you would calculate the amount to be entered to be $354.70, rather than rounding $120.30 to $120 and $234.40 to $234 so that the total would be $354.
- 2). Round the calculated amount down to the nearest dollar if the number of cents is below 50. For example, if the amount you are supposed to enter equals $164.29, the IRS allows you to enter $164 to make your calculations easier.
- 3). Round the calculate amount up to the nearest dollar of the number of cents is equal to 50 or more. For example, if you were supposed to enter $354.70, you could enter $355 to make the calculations easier.
- 4). Repeat the process each time you are entering amounts onto your tax return. If you round once, you must round every time.
Source...