Amortisation Schedule Explained (Australia)

An amortisation schedule (also called a loan interest or repayment schedule) shows how each repayment on a principal-and-interest home loan is split between interest — the cost of borrowing — and principal, which reduces what you owe, plus the balance remaining after each payment. On a typical 30-year loan, most of each early repayment is interest; the split only tips towards principal after about two-thirds of the term.

See your own schedule: Home Loan Repayment Calculator

Example: $600,000 over 30 years at 6.45%

Monthly repayments of $3,773 (principal and interest). Over the full term you'd repay about $1,358,172, of which $758,172 is interest.

Year	Interest paid that year	Principal repaid that year	Share of repayments that is interest	Balance at end of year
1	$38,502	$6,770	85%	$593,230
2	$38,052	$7,220	84%	$586,010
3	$37,573	$7,700	83%	$578,310
5	$36,515	$8,757	81%	$561,342
10	$33,193	$12,079	73%	$508,017
15	$28,611	$16,662	63%	$434,462
20	$22,289	$22,983	49%	$333,002
25	$13,570	$31,702	30%	$193,049
30	$1,543	$43,730	3%	$0

Calculated with monthly compounding and the rate unchanged for 30 years, using the same amortisation engine as MoneyWiseCalc's calculators. Real loans change as rates move.

Why the early years feel slow

Interest each month is charged on the balance you still owe. At the start the balance is highest, so interest takes most of the repayment: in the first month above, $3,225 is interest and only $548 reduces the loan. As the balance falls, interest shrinks and more of the same repayment goes to principal. In this example:

• principal repaid first exceeds interest in year 20
• half the loan is repaid after about 21 years (month 256)

How rates, terms and extra repayments change the schedule

Change (same $600,000 loan)	Monthly repayment	Total interest over the loan
30 years at 6.45% (example above)	$3,773	$758,172
30 years at 7.45% (rate 1 percentage point higher)	$4,175	$902,915
25 years at 6.45%	$4,033	$609,755

• A higher rate raises the repayment and shifts even more of the early repayments to interest.
• A shorter term raises the repayment but cuts total interest sharply — here by about $148,000.
• Extra repayments and money in an offset account reduce the balance that interest is charged on, so every later repayment does more work. Compare them in the Offset Calculator and our guide to extra repayments.

Interest-only periods

During an interest-only period the schedule shows no principal at all — the balance stays the same. When it ends, the full balance must be repaid over the remaining (shorter) term, so repayments jump. See principal and interest vs interest-only.

How to use a schedule in practice

• Check how much you'll still owe at a future date (for example, when a fixed rate ends or before you sell).
• Compare two rates or terms side by side before refinancing — the Refinance Calculator also shows the balance difference.
• Test monthly versus fortnightly repayments, and the effect of an extra amount each month.

Frequently asked questions

Does the schedule change if interest rates change?

Yes. On a variable loan, a rate change resets the repayment and the interest/principal split from that point on. Lenders usually recalculate repayments so the loan still finishes on the original date.

Why is so much of my repayment interest?

Interest is charged on the balance owing, which is largest at the start. On a 30-year loan at around 6.5%, roughly 85% of first-year repayments are interest.

Is a loan interest schedule the same as an amortisation schedule?

Yes — both describe the period-by-period split of repayments between interest and principal, and the balance remaining.

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Important: General information only. Figures are estimates that assume a constant rate and no fees; your lender's statements show your actual schedule.