Last Mortgage PaymentWhat Is an Amortization Schedule?
An amortization schedule is a month-by-month table of your loan. For every payment it shows how much goes to interest, how much goes to principal, and what you still owe afterward. It's the clearest way to see where your money goes, and why extra payments are so powerful.
How each payment is split
A fixed-rate mortgage has the same principal-and-interest payment every month. Each month:
- Interest = your remaining balance × (annual rate ÷ 12)
- Principal = your payment − that interest
- New balance = old balance − principal
As the balance shrinks, the interest shrinks, so more of each payment goes to principal.
A real example
A $300,000 loan at 6.5% for 30 years has a payment of $1,896.20.
| Payment | Interest | Principal | Notes |
|---|---|---|---|
| #1 | $1,625.00 | $271.20 | $300,000 × 6.5% ÷ 12 = $1,625 interest |
| #180 (year 15) | $1,182.95 | $713.25 | Halfway through the term |
| #233 (year 20) | $946.50 | $949.70 | First month principal is larger than interest |
| #360 (last) | $10.22 | $1,885.99 | Almost all principal |
In the first month, 86% of the payment is interest. Principal doesn't overtake interest until payment 233, more than 19 years in. After 10 years of payments you'd still owe about $254,328, having paid about $181,873 in interest.
Where the payment comes from
The monthly payment comes from the standard loan formula:
Payment = P × r ÷ (1 − (1 + r)−n)
- P = loan amount
- r = monthly interest rate (annual rate ÷ 12)
- n = number of payments (years × 12)
This is the payment that brings the balance to exactly zero after the last payment.
How extra payments change the schedule
An extra principal payment lowers the balance right away. Every later month then charges less interest, so more of your regular payment goes to principal. That's why the schedule gets shorter: your required payment stays the same, but the loan ends years earlier.
This is also why early extra payments are worth the most. At the start of the loan, the balance is largest and there are the most months of interest left to avoid. See how much $100 extra a month saves for the numbers.
Reading the schedule in our calculator
The calculator shows your full schedule below the results:
- Yearly view totals each year. Click a year to see its months.
- Monthly view shows every payment.
- Highlighted rows mark months where an extra-payment change starts or a one-time payment is made.
- Download CSV opens it in Excel or Google Sheets.
Your actual statement may differ by a few cents. Lenders round each payment to the cent and may count interest days slightly differently.
This article is general information, not financial advice. Examples are rounded and assume a fixed-rate loan; your lender's numbers may differ slightly.