<prompt> Human: Any advice on how to calculate what my tax withholding allowances should be in order to zero out at the end of the year? E.g., dont owe money no refund?Ive been told its not an exact science, so just looking for some basic estimation principles.  <response>: If youre looking for getting close to zero, there isnt anything better from what Ive heard than the IRSs own Withholding Calculator 