To calculate the Total interest, you will use the Cumulative Interest formula (=CUMIPMT). Loan amortization schedules in Workday Adaptive Planning are slightly different than those done in Excel.Keep reading to learn more. Amortization calculation depends on the principal, the Rate of interest, and the time period of the loan. Use this free mortgage calculator to estimate your monthly mortgage payments and annual amortization. For a printable payment schedule, click on "Create Amortization Schedule" and a new browser window will open. In the mortgage amortization table for 240 months seen in Section 8.3. Solving gives the monthly payment , a , as demonstrated earlier.