Mortgage lenders measure your PITI against your income to determine whether you qualify for a loan. According to the 28% rule, the percentage of your income that goes to your mortgage shouldn’t exceed 28% of your gross monthly income, which is your salary before deductions.nnThe lower your percentage, the more willing lenders will be to offer you a loan. If your PITI is too high, consider making a higher down payment, finding a less expensive home or increasing your income.