Calculator
Amortisation Schedule Calculator
How does the split between interest and principal move over time?
The loan
Overpayments (optional)
Scheduled payment
—
cleared in — · — of interest
- Total repaid
- —
- Interest per $1 borrowed
- —
- Principal overtakes interest
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- Half the balance cleared
- —
Where each year's money goes
Interest falls as the balance does; principal rises to meet it.
Lifetime split
The full schedule
Switch between one row per payment and one row per year. The table scrolls inside its own frame.
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Illustrative figures — here is exactly what this assumes
- Fixed rate for the whole term; no reset, recast or rate change.
- Payments applied on schedule, monthly, in arrears.
- Extra payments applied to principal in the month you set.
- Interest calculated on the balance at the start of each month.
- Tax, insurance and mortgage insurance are excluded — this is the loan only.
- Figures are illustrative and are not a quote or a Loan Estimate.
This calculator provides estimates for educational purposes only. Results are not a Loan Estimate, pre-approval, or commitment to lend, and may not reflect taxes, insurance, HOA dues, or other costs. Contact a loan officer for an accurate quote.
Rates shown are for illustrative purposes only, are not a quote or guarantee, and do not reflect a specific offer. Actual rates depend on credit score, loan amount, loan-to-value, occupancy, and other factors, and change daily. Contact us for a personalized rate quote.
Turn the estimate into a number
A calculator uses averages. A loan officer uses your file.
Property taxes, insurance and mortgage insurance all move by county, by carrier and by credit profile. If you want a figure you can plan around, that is the conversation to have.
- No credit pull to start a conversation
- Plain answers, including "this is not the right time"
- You can stop at any point
This is a demonstration website. The form below validates and confirms, but nothing is sent and nothing is stored. Nobody will call you.
Thank you, there.
On a live site this would reach a loan officer and you would hear back the same working day. On this demonstration nothing was sent, nothing was stored, and nobody will contact you.
If you want to reach a real person about this demo, the site owner is athello@summitcrestmortgage.com.
Keep going
- Monthly PaymentPrincipal, interest, tax, insurance, HOA and PMI — itemised.
- AffordabilityIncome, debts and DTI turned into a defensible price range.
- Refinance & Break-evenNew rate against closing costs, and the month it pays back.
- Extra PaymentsOne-off and recurring overpayments against interest and months saved.
- Rent vs BuyBoth paths over a holding period, with every assumption exposed.
Calculator FAQ
Questions about amortisation
What is an amortisation schedule?
It is the payment-by-payment plan for clearing a loan. Each row shows how much of that payment goes to interest, how much reduces the balance, and what is left owing afterwards. On a fixed-rate mortgage the payment stays the same while the split inside it shifts steadily from interest towards principal.
Why is so much of an early payment interest?
Interest is charged on what you still owe. At the start you owe nearly the whole loan, so the interest slice is large and very little of the payment reduces the balance. As the balance falls, so does the interest charge, and more of the same payment goes to principal. The switchover point on a 30-year loan at typical rates is usually somewhere around year 18 to 20.
What is the difference between the month and year views?
The month view is the real schedule — one row per payment. The year view adds twelve months together into a single row, which makes long loans readable and is usually the better view for spotting the shape. Both are the same arithmetic.
Does the schedule change if I overpay?
Yes, substantially, because every extra dollar comes straight off the balance and stops accruing interest immediately. Set an extra amount below and watch the final row move; the extra payment calculator gives that its own page with the interest and months saved worked out.