Economics
Principal Repayment
Quick fact
In a typical 30-year mortgage with a 6% interest rate, the first payment may allocate less than 10% toward principal reduction—the rest goes to interest.
Why this is interesting
When you make a monthly loan payment, only part of it actually reduces what you owe. Can you guess why your balance seems to barely move at first?
Read the full explanation
Understanding Principal Repayment
Imagine borrowing $10,000 from a friend with the agreement to pay back $200 each month. If your friend charges 5% interest per year, your first payment doesn't all go to reducing the $10,000. Instead, a portion covers the 'cost' of borrowing (the interest), and the remaining amount lowers the principal. Over time, as the principal shrinks, less interest accrues, so more of your fixed payment goes toward the principal. This shift is why late payments feel more 'productive'—they finally make a big dent in the original debt.
A deeper explanation
Lenders calculate interest on the outstanding principal balance. Each payment is divided according to an amortization formula: interest for that period is first computed (principal × periodic interest rate), then the remainder of the payment is applied to reduce the principal. This dynamic creates an amortization schedule—a table showing the split for each payment over the loan's life. The underlying principle is that interest is a function of remaining debt; thus, early payments have a large interest component. Understanding this mechanism is crucial because it explains why making extra principal payments early can drastically reduce total interest paid and shorten the loan term. It also highlights the true cost of long-term debt and informs strategies like paying down high-interest loans first.