Buying a Home (Mortgage Payment) Calculator Before buying a home, it's likely that many questions will arise, particularly in regard to financing. For example: What will the monthly payment be? How will the loan term affect the monthly payment (e.g., 15-year, 30-year)? How will the interest rate affect the monthly payment? Enter the required values to calculate the monthly payment. An annual amortization chart and a chart comparing total principal and interest payments will be generated. Loan amount $ Annual interest rate % Term 1 year 2 years3 years4 years5 years6 years7 years8 years9 years10 years11 years12 years13 years14 years15 years16 years17 years18 years19 years20 years21 years22 years23 years24 years25 years26 years27 years28 years29 years30 years31 years32 years33 years34 years35 years36 years37 years38 years39 years40 years