The tutorial shows how to build an amortization schedule in Excel to detail periodic payments on an amortizing loan or mortgage. Note: this spreadsheet is for educational purposes only.5, A fixed principal loan results in declining payments over the loan period. In this tutorial we're going to learn how to build a simple loan calculator application in Excel. This calculator will help you figure out your regular loan payments and it will also create a detailed schedule of payments. LendingTree's personal loan payment calculator can help you see how much your loan could cost, including principal and interest. Check out the web's best free mortgage calculator to save money on your home loan today. Home Equity Loan Calculator. Our calculator estimates the maximum amount you're likely to qualify for, along with your monthly payments. Since the total principal balance declines each month, you pay less interest in the balance.