Loan amortization schedule. 3. 4, Enter values, Loan summary.I'm looking for a Biweekly Loan Amortization Schedule that will allow me to input various additional payments depending on ability. The tutorial shows how to build an amortization schedule in Excel to detail periodic payments on an amortizing loan or mortgage. Streamline your loan repayments with a biweekly amortization schedule in Excel. Learn how to create a customized schedule that suits your financial needs. That ends in 13 total monthly payments a year vs. The 12 made in a typical repayment schedule.