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Mortgage Repayment Calculator

Estimate your repayments, total interest, and view a full yearly amortisation schedule. Supports weekly, fortnightly and monthly frequencies.

Updated April 2026·Free, no sign-up

Loan Details

Loan Amount

$50K$5M

Interest Rate (% p.a.)

1%15%

Loan Term

Repayment Frequency

Loan Type

Monthly Repayment

$3,160

30-year monthly repayments

Total Repayments$1,137,722

Total Interest Paid$637,722

Principal$500,000

Principal vs Interest Breakdown

Principal 44%Interest 56%

This calculator provides estimates only and does not constitute financial advice. Actual repayments may vary. Always consult a financial professional.

Amortization Schedule

Yearly breakdown

Year	Opening Balance	Principal	Interest	Closing Balance
1	$500,000	$5,589	$32,335	$494,411
2	$494,411	$5,963	$31,961	$488,448
3	$488,448	$6,362	$31,562	$482,086
4	$482,086	$6,788	$31,136	$475,298
5	$475,298	$7,243	$30,681	$468,055
6	$468,055	$7,728	$30,196	$460,327
7	$460,327	$8,246	$29,678	$452,081
8	$452,081	$8,798	$29,126	$443,283
9	$443,283	$9,387	$28,537	$433,896
10	$433,896	$10,016	$27,908	$423,881
11	$423,881	$10,686	$27,238	$413,194
12	$413,194	$11,402	$26,522	$401,792

What to do next

Pair this with…

Stamp duty

What stamp duty actually costs in your state.

Borrowing power

What lenders will let you borrow on your income.

How much deposit do I need?

5%, 10%, 20%, plus government schemes and FHSS.

What you’re actually paying for

Every monthly mortgage repayment is split between two things: a chunk that goes against your loan balance (principal) and a chunk that pays the lender for letting you have the money in the first place (interest). The split changes over the life of the loan.

In year one of a 30-year, $600,000 loan at 6%, the vast majority of every repayment is interest. By year 25, the same repayment is mostly principal. The amortisation table the calculator produces shows that shift visually.

~$695k

Total interest you'd pay over 30 years on a $600,000 loan at 6%, approximately doubling the original loan amount in interest alone.

Estimate, principal and interest, monthly

The biggest levers on total interest paid

Repayment frequency

Switching from monthly to fortnightly repayments at the same monthly amount means you make 26 payments a year instead of 12, the equivalent of 13 monthly payments. That extra payment a year reduces principal faster and can save 4 to 5 years off a 30-year loan.

Loan term

A 25-year term costs less in total interest than a 30-year term but with higher monthly repayments. The trade-off is monthly cash flow vs lifetime cost.

Extra repayments

Even modest extra repayments compound powerfully. An extra $200 a month on a $600,000 loan can shave several years and tens of thousands of dollars off total interest. Variable-rate loans usually allow extra repayments without penalty; fixed-rate loans typically cap extras (often $10,000 a year) or charge a break fee.

Offset account

Money in an offset account reduces the interest charged on your loan without locking it away, you can withdraw it any time. For most owner occupiers, an offset account is a better tool than direct extra repayments because it preserves liquidity.

The rate isn't the only thing that matters

When comparing loans, look at fees (annual, monthly, discharge), redraw and offset features, the lender’s revert rate after any honeymoon period, and how the rate is calculated (some lenders charge a higher rate on the borrowed amount, some on the average daily balance). The comparison rate on a loan is meant to capture most of these in one number, but always sanity-check.

What this calculator doesn’t do

It doesn’t apply LMI (Lenders Mortgage Insurance) when LVR exceeds 80%, see our LMI guide.
It doesn’t model split-rate loans (part fixed, part variable).
It doesn’t factor in offset balance reductions, run those scenarios separately.
It doesn’t cover construction loans (interest charged on drawn amount only).

For a precise quote on your specific situation, a mortgage broker can compare 30+ lenders for you in one process. Get connected if you want a free intro to one.

Want a real broker to run the numbers properly?

Calculator estimates are a starting point. A mortgage broker can compare 30+ lender policies and tell you what you’ll actually be approved for. Free for buyers, no commitment.

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Common questions

How is a mortgage repayment calculated?

For a principal-and-interest loan, repayments are calculated using the formula: P × (r(1+r)^n) / ((1+r)^n − 1), where P is the loan amount, r is the periodic interest rate, and n is the total number of payments. For interest-only loans, the repayment is simply the loan amount multiplied by the periodic interest rate.

What is the difference between fortnightly and monthly repayments?

Making fortnightly repayments results in 26 payments per year, the equivalent of 13 monthly payments. This extra payment each year reduces your principal faster, shortening the loan term and saving interest over the life of the loan.

What does an interest-only loan mean?

With an interest-only loan your repayments cover only the interest charged each period. The loan principal does not reduce during the interest-only period. These loans are common for investment properties but result in higher total repayments over the life of the loan.

How much deposit do I need for a home loan in Australia?

Most Australian lenders require a minimum 20% deposit to avoid Lenders Mortgage Insurance (LMI). Some lenders accept deposits as low as 5 to 10% with LMI. First home buyers may also be eligible for government schemes that reduce the required deposit, see our First Home Buyer Guide.

Should I make extra repayments if I have an offset account?

An offset account effectively reduces the interest you pay without locking your money away. Money in offset is identical to money in extra repayments in terms of interest savings, but stays accessible. If you want flexibility, prefer offset; if you want to force discipline, prefer direct extra repayments. The interest saving is the same.

How does loan term affect total interest?

A longer loan term means lower monthly repayments but dramatically higher total interest. A 25-year loan vs a 30-year loan on $600,000 at 6% saves around $130,000 in total interest, though the monthly repayments are about $300 higher. Use the calculator to compare.