1. A computer implemented system for determining an amount of mortgage interest tax impact available to a borrower, comprising: a computer having computer-readable instructions stored therein, the computer and computer-readable instructions in combination implementing: a mortgage information interface configured to receive information related to a mortgage loan, the mortgage loan including an inflationary index provision; a total tax impact calculator configured to determine a total mortgage interest tax impact available based on an amount of mortgage interest paid and an amount of an adjustment to an outstanding principal balance based on the inflationary index provision; and a reporting engine configured to provide the total mortgage interest tax impact available.