Use this mortgage calculator to determine your monthly payment and generate an estimated amortization schedule. Watch as a build a fully dynamic, mortgage amortization in Excel.Calculator 15 Yr Rates 30 Yr Rates. (Helps to find out how long you'll be paying PMI). . The 2025 Financial Planning Cheat Sheet is here and it's FREE! With our inputs converted into the right units, we're now ready to build our mortgage amortization table in Excel. Enable Your Worksheet to Calculate Your Loan Payments. How to Enable Your Mortgage Calculation Spreadsheet.