Estimate your 1997 adjusted gross income (or copy it from Line 31 of IRS Form 1040). Your AGI is your gross income reduced by any of a variety of "above-the-line" deductions. These can include: deductions for IRA contributions, moving expenses, penalties on early withdrawal of savings, and alimony payments. Personal deductions, such as for home mortgage interest or any of the other items on Schedule A, don't affect AGI.