What it means to amortize
Amortizing a loan just means paying it off in scheduled instalments that each cover the interest due first and chip at principal with whatever's left. Do that long enough and the balance walks down to zero on the final payment.
How to read the schedule
An amortization schedule is four columns per row: the payment, the interest part, the principal part and the balance still owed. On a fixed-rate loan the payment never moves, but watch the other three — interest keeps falling and principal keeps climbing as the balance drops.
| Loan: 200,000 at 6% for 30 years | |
| Monthly payment | ~1,199 |
| Payment 1 — interest / principal | 1,000 / 199 |
| Payment 360 — interest / principal | ~6 / ~1,193 |
Equal instalment vs equal principal
Two common shapes. Equal monthly instalment holds the total payment flat every month. Equal principal repays the same slice of principal each month and adds interest on what's left, so payments start high and ease off. Equal principal usually costs less interest overall, but it asks for more cash in the early years.
Why the early years carry the weight
Interest rides on the outstanding balance, and the balance is biggest at the start — so the opening years are where most of the interest lives. Pay extra principal early and you erase interest that would have stacked up across the entire remaining term. That's the whole case for prepaying sooner rather than later.
Putting the schedule to work
- Read off the total interest, not just the monthly payment.
- Find the balance at any future date — handy if you might sell or refinance.
- Drop in an extra payment and watch how many months and how much interest it wipes out.
Building all that by hand is miserable, so let a calculator print the month-by-month table, then check the totals against your contract.
The part most people miss the first time they read a schedule: in the early years you barely touch the principal. On a 30-year loan it can take a decade before half your payment goes to the balance — which is exactly why an extra payment in year one is worth far more than the same payment in year twenty.
Frequently asked questions
What is negative amortization?
It happens when a payment does not even cover the interest due, so the unpaid interest is added to the balance and the loan grows instead of shrinking.
Why does the principal portion grow each month?
The payment is fixed but interest is charged on a falling balance, so less goes to interest and more to principal over time.
Is equal-principal better than equal installment?
Equal-principal usually means less total interest but higher early payments. Equal installment keeps payments steady and easier to budget.
Can I get an amortization schedule before borrowing?
Yes. Any amortization calculator can produce the full schedule from the amount, rate and term so you can plan ahead.
The schedule here is a plain amortization table: each payment's interest is the remaining balance times the monthly rate, and the rest reduces principal until it reaches zero.
This article is for general education only and is not financial, tax or lending advice. Rates, fees and approval decisions are set by your bank or lender; always confirm figures against an official loan offer before deciding.