UNDERSTAND THE ANSWERHow is this calculated?
Each month’s interest equals the opening balance times the monthly rate. The rest of the scheduled payment plus any extra amount reduces principal.
Fixed-rate amortizationPayment = P × [r(1 + r)ⁿ] ÷ [(1 + r)ⁿ − 1]
A practical example
A $300,000 loan at 6.5% for 30 years requires about $1,896 monthly before taxes, insurance and fees.