Real Estate Investing Glossary
Amortization
Last reviewed 2026-07-15
Amortization is the scheduled repayment of a loan where each fixed payment covers interest plus a growing slice of principal until the balance hits zero.
What is amortization?
Amortization is how installment loans are structured to be fully repaid over a set term. Each payment on a 30-year fixed mortgage is identical, but its composition shifts: early payments are mostly interest (computed on the large remaining balance), while later payments are mostly principal. The schedule showing this split month by month is the amortization schedule.
The front-loading surprises many first-time borrowers. On a $200,000 loan at 7%, the first monthly payment of $1,331 includes about $1,167 of interest and only $164 of principal. It takes roughly 20 years before the principal portion of the payment exceeds the interest portion, and extra principal payments early in the loan save far more interest than the same payments made late.
For rental investors, amortization is a quiet fourth return stream: the tenant’s rent pays down the loan, converting debt into equity every month even if the price never moves. Interest-only loans and the interest-only periods on some commercial debt skip this benefit in exchange for lower payments, and loans with a balloon payment amortize on a long schedule but come due early.
Worked example
On a $200,000, 30-year loan at 7%, the payment is $1,330.60. In month one, $1,166.67 goes to interest and $163.93 to principal. By year 10 the balance is about $171,600, and by year 20 about $111,900, the paydown accelerates as interest accrues on an ever-smaller balance.
Frequently asked questions
- Why is so much of my early mortgage payment interest?
- Because interest is charged each month on the outstanding balance, and the balance is largest at the start. A 7% annual rate on $200,000 generates about $1,167 of interest in month one, so a $1,331 payment can only spare $164 for principal. As the balance falls, the interest charge shrinks and the principal share grows, slowly at first, then quickly in the final decade.
- Do extra principal payments change my monthly payment?
- On a typical fixed-rate mortgage, no, extra principal shortens the loan and cuts total interest, but the required monthly payment stays the same. Paying one extra monthly payment per year on a 30-year loan retires it roughly five to six years early. If you want a lower required payment instead, you would need to refinance or request a recast, where the lender re-amortizes the reduced balance over the remaining term.
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