Open Excel and create headers for Loan Amount, Interest Rate, Loan Term, Payment, Period, Beginning Balance, Payment, Interest, Principal, and Ending Balance
Enter the loan details in separate cells for the principal, annual interest rate, and number of months or years
Convert the annual interest rate to a monthly rate if needed by dividing by 12
Calculate the monthly payment using the PMT function
Set up the first period row with the beginning balance equal to the loan amount
Calculate interest for each period by multiplying the beginning balance by the periodic interest rate
Calculate principal for each period by subtracting interest from the payment
Calculate the ending balance by subtracting principal from the beginning balance
Use the ending balance from the previous row as the beginning balance for the next row
Copy the formulas down for all payment periods
Format the cells as currency and percentages
Review the final ending balance to confirm it reaches zero or close to zero due to rounding
Adjust formulas or add a final payment correction if necessary