Amortization is the process of paying off a loan through regular, fixed payments over a set period. Each payment is split between two things: the interest you owe and the principal (the original amount borrowed).
The key idea — the split changes over time:
- Early in the loan, a larger share of each payment goes toward interest, and less toward principal.
- Later in the loan, the balance is smaller, so less of each payment is interest and more goes toward principal.
- Your total payment stays the same each month — only the split shifts.
The amortization schedule: this is a table showing every payment over the life of the loan and exactly how much of each one goes to interest versus principal. It also shows the remaining balance after each payment.
Where you see amortization: it is standard for installment loans — mortgages, auto loans, and personal loans.
Why it matters to you: because early payments are interest-heavy, extra payments made directly toward principal can noticeably reduce the total interest you pay and shorten the loan. Even small additional principal payments add up.
Understanding amortization pairs well with knowing the difference between APR and interest rate when you compare loan offers.