The term "amortization" comes from the Old French amortir , meaning "to kill." In finance, it refers to "killing off" a debt over time.
Mortgage mathematics is the study of the financial mechanics behind long-term property financing. While a mortgage may appear to be a simple loan, it is governed by the principles of , time value of money (TVM) , and compound interest . At its core, mortgage math seeks to determine how a fixed monthly payment can simultaneously pay down interest and reduce the principal balance over a set horizon. 1. The Foundation: Time Value of Money mortgage mathematics
The Architecture of Interest: An Analysis of Mortgage Mathematics The term "amortization" comes from the Old French
The mathematics becomes more complex with . Unlike fixed-rate loans, ARMs use a variable At its core, mortgage math seeks to determine
M=Pr(1+r)n(1+r)n−1cap M equals cap P the fraction with numerator r open paren 1 plus r close paren to the n-th power and denominator open paren 1 plus r close paren to the n-th power minus 1 end-fraction = Total monthly payment P = Principal loan amount r = Monthly interest rate (annual rate divided by 12) n = Total number of payments (months) 2. The Amortization Process
In the early stages of a mortgage, the majority of the monthly payment is directed toward interest. This is because interest is calculated based on the remaining principal. As the principal decreases, the interest portion of the payment shrinks, allowing a larger share of the payment to be applied to the principal. This creates a "snowball effect" where the equity in the home grows at an accelerating rate toward the end of the loan term. 3. The Impact of Compounding and Frequency