Mortgage Amortization Inputs Loan principal amount Annual interest rate Loan period in years Base year of loan Base month of loan Payments in First 12 Months Year 0 Month Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Beginning Balance Payment Principal Interest Cumulative Cumulative Ending Principal Interest Balance Key Figures Annual loan payments Monthly payments Interest in first calendar year Interest over term of loan Sum of all payments Yearly Schedule of Balances and Payments Year Beginning Balance Payment Principal Interest Cumulative Cumulative Ending Principal Interest Balance