What Your Loan Amortization Schedule Really Shows

Front-loaded amortization. In year one of a 30-year mortgage, the payment is approximately 87% interest and 13% principal. After one full year of payments, a $400,000 loan at 7% has only been reduced to approximately $394,000 — despite paying over $31,000 in payments. This is mathematically correct, not a bank error. The interest charge is calculated monthly on a very large outstanding balance, leaving little room for principal reduction.

Yes. A refinance creates a new loan with a new amortization schedule starting from scratch. If you refinance a 30-year mortgage in year 10 into a new 30-year mortgage, you extend your payoff date by 10 years relative to the original loan (though you can choose a shorter term at refinance). Even if the new rate is lower, extending the amortization period can cost more in total interest than staying on the original schedule. Always model total interest paid on both paths, not just the monthly payment change.

An ARM amortizes the same way during its fixed initial period. When the rate adjusts (after the initial 3, 5, or 7 years typically), the new payment is recalculated to pay off the remaining balance over the remaining term at the new rate. This can cause payment jumps if rates rise. The principal balance at the adjustment point determines the new payment — verify your remaining balance and understand the adjustment cap structure before choosing an ARM.

Yes. Your lender is required to provide an amortization schedule upon request. You can also generate one from any loan amortization calculator using your exact loan balance, interest rate, and remaining term. Your monthly mortgage statement shows your payment allocation for each month, though not the full future schedule. Knowing where you are on the schedule helps you make informed decisions about extra payments and refinancing.

A 15-year mortgage at the same rate builds equity roughly twice as fast as a 30-year mortgage — because the higher payment reduces the balance more quickly, reducing the interest charge on each subsequent payment. Total interest on a $400,000 mortgage at 7%: approximately $225,000 over 15 years versus $558,000 over 30 years. The 15-year saves $333,000 in interest but requires a significantly higher monthly payment ($3,593 vs $2,661).

A negative amortization loan allows payments below the full interest charge — the unpaid interest is added to the principal balance, causing the loan balance to grow over time even while making payments. These were common in the pre-2008 mortgage era (option ARMs) and contributed to the foreclosure crisis. They are now heavily regulated for consumer mortgages. Never accept a loan where minimum payments do not cover the full interest charge — your balance will grow, not shrink.