Mortgage repayment calculator for Australian home loans
This mortgage repayment calculator (also called a home loan or housing loan repayment calculator) works out your repayments and total interest from the loan amount, rate, term and repayment frequency. A $600,000 loan at 6.23% over 30 years costs about $3,687 a month. Add extra repayments, a lump sum, an offset balance or an interest-only period to see the interest and time you'd save. It works with any lender's rate, including CommBank, Westpac, NAB, ANZ, St.George and Suncorp: it uses the standard principal and interest formula that lenders' own calculators use, so for the same rate, loan amount and term the monthly repayment matches.
Last reviewed
Mortgage repayment calculator
Repayments and total interest, with optional extra repayments, an offset account or an interest-only period.
Assumed to stay the same for the life of the loan.
Repayments jump when the interest-only period ends, because the loan is repaid over the years left.
Monthly repayment
$3,686.50
| Loan amount | $600,000 |
|---|---|
| Interest rate | 6.23% a year |
| Time to repay | 30 years |
| Total repayments | $1,327,141 |
| Total interest paid | $727,141 |
Year-by-year balance
| Year | Interest | Principal repaid | Balance |
|---|---|---|---|
| 1 | $37,181 | $7,057 | $592,943 |
| 2 | $36,728 | $7,510 | $585,433 |
| 3 | $36,247 | $7,991 | $577,442 |
| 4 | $35,735 | $8,503 | $568,938 |
| 5 | $35,189 | $9,049 | $559,890 |
| 6 | $34,609 | $9,629 | $550,261 |
| 7 | $33,992 | $10,246 | $540,015 |
| 8 | $33,335 | $10,903 | $529,112 |
| 9 | $32,636 | $11,602 | $517,510 |
| 10 | $31,892 | $12,346 | $505,164 |
| 11 | $31,101 | $13,137 | $492,027 |
| 12 | $30,259 | $13,979 | $478,048 |
| 13 | $29,362 | $14,876 | $463,172 |
| 14 | $28,409 | $15,829 | $447,343 |
| 15 | $27,394 | $16,844 | $430,499 |
| 16 | $26,314 | $17,924 | $412,575 |
| 17 | $25,165 | $19,073 | $393,501 |
| 18 | $23,942 | $20,296 | $373,205 |
| 19 | $22,641 | $21,597 | $351,608 |
| 20 | $21,256 | $22,982 | $328,627 |
| 21 | $19,783 | $24,455 | $304,172 |
| 22 | $18,215 | $26,023 | $278,149 |
| 23 | $16,547 | $27,691 | $250,458 |
| 24 | $14,772 | $29,466 | $220,991 |
| 25 | $12,882 | $31,356 | $189,636 |
| 26 | $10,872 | $33,366 | $156,270 |
| 27 | $8,733 | $35,505 | $120,765 |
| 28 | $6,457 | $37,781 | $82,984 |
| 29 | $4,035 | $40,203 | $42,781 |
| 30 | $1,457 | $42,781 | $0 |
Stress test this loan at higher rates, or see how much you can borrow.
An estimate: interest is charged at the repayment frequency and the rate never changes. It leaves out fees, redraws and rate changes, and assumes the lender accepts extra repayments. Check fixed rate loans for an extra repayment limit, and confirm figures with your lender.
How the calculator works
The calculator uses the standard amortisation formula that Australian lenders use for principal and interest loans. It finds the single repayment that, paid every period for the whole term, covers each period's interest and repays the loan to exactly zero:
Repayment = P × r × (1 + r)n ÷ ((1 + r)n − 1)
- P is the loan amount.
- r is the rate per repayment period: the annual rate divided by 12 (monthly), 26 (fortnightly) or 52 (weekly).
- n is the number of repayments: the term in years times 12, 26 or 52.
Total repayments are the repayment times the number of repayments, and total interest is total repayments less the loan amount. Early repayments are mostly interest; as the balance falls, more of each repayment goes to principal.
Home loan repayments on common loan sizes
Use this table to sense-check your numbers. A 0.5 percentage point difference in rate changes the repayment on a $600,000 loan by about $195 a month, which is why comparing rates matters.
| Loan amount | 5.50% | 6.00% | 6.23% | 6.50% | 7.00% |
|---|---|---|---|---|---|
| $400,000 | $2,271 | $2,398 | $2,458 | $2,528 | $2,661 |
| $500,000 | $2,839 | $2,998 | $3,072 | $3,160 | $3,327 |
| $600,000 | $3,407 | $3,597 | $3,687 | $3,792 | $3,992 |
| $700,000 | $3,975 | $4,197 | $4,301 | $4,424 | $4,657 |
| $800,000 | $4,542 | $4,796 | $4,915 | $5,057 | $5,322 |
| $1,000,000 | $5,678 | $5,996 | $6,144 | $6,321 | $6,653 |
Monthly, fortnightly or weekly repayments?
This calculator works out true fortnightly and weekly repayments: the rate and the term are divided into 26 or 52 periods. That costs almost exactly the same as paying monthly. The saving people talk about comes from paying half your monthly repayment every fortnight: 26 half-payments equal 13 monthly repayments a year instead of 12, and the extra month goes straight off the balance.
| Repayment method | Repayment | Time to repay | Total interest |
|---|---|---|---|
| Monthly | $2,997.75 a month | 30 years | $579,191 |
| Fortnightly (true fortnightly, as this calculator works) | $1,382.92 a fortnight | 30 years | $578,674 |
| Weekly (true weekly) | $691.32 a week | 30 years | $578,452 |
| Half the monthly repayment every fortnight | $1,498.88 a fortnight | About 24.5 years | $455,131 |
You can get the same effect on any loan that allows unlimited extra repayments, by adding one-twelfth of a monthly repayment to each payment. On a fixed loan, check the extra repayment limit first; our fixed vs variable guide lists each lender's cap.
Extra repayments, offset and interest-only
Open the options in the calculator to add a regular extra repayment, a one-off lump sum, an offset balance or an interest-only period. It runs the loan both ways and shows the interest saved, how much sooner it is repaid and the balance at the end of each year.
| Option | Interest saved | Paid off sooner by |
|---|---|---|
| Extra $100 a week (weekly repayments) | $205,063 | 7 years and 4 months |
| $30,000 kept in an offset account | $141,574 | 3 years and 2 months |
| $20,000 lump sum at the start | $98,848 | 2 years and 8 months |
| 5 years interest-only first | $44,940 more interest | No change |
- Extra repayments go straight off the balance, so every later repayment carries less interest. Variable loans usually allow unlimited extra repayments; fixed loans often cap them, which our fixed vs variable guide lists by lender.
- An offset account reduces the balance interest is charged on without locking the money away. The calculator keeps the balance constant; in practice it rises and falls with your pay and spending. See how offset accounts work.
- Interest-only lowers repayments at the start, then they rise because the loan is repaid over fewer years: $3,115 a month for 5 years on our example, then $3,951 instead of $3,687 from day one. See investment loans.
Interest-only mortgage repayment calculator
An interest-only repayment covers the interest and nothing else, so it is the loan times the rate divided by 12: $3,115 a month on $600,000 at 6.23%. When the interest-only period ends, the loan is repaid over the years left, so the repayment jumps above what principal and interest would have cost from the start. Moneysmart's advice is to work out that higher repayment before you commit.
| Loan | Interest-only repayment (first 5 years) | Principal and interest after that (25 years) | Principal and interest from day one |
|---|---|---|---|
| $400,000 | $2,077 | $2,634 | $2,458 |
| $600,000 | $3,115 | $3,951 | $3,687 |
| $800,000 | $4,153 | $5,267 | $4,915 |
To run your own loan, open the calculator with a five-year interest-only period already set:
Use the calculator in interest-only modeStamp duty and upfront costs by state
The loan is only part of the cost of buying. Stamp duty usually comes from your savings on top of the deposit, and it varies more between states than repayments do. The table shows the duty on a $700,000 established home for an owner-occupier and an eligible first home buyer in each state, with a link to each state's calculator.
| State or territory | Owner-occupier | First home buyer | Work it out |
|---|---|---|---|
| New South Wales | $25,687 | $0 | NSW stamp duty calculator |
| Victoria | $37,070 | $24,713 | VIC stamp duty calculator |
| Queensland | $17,350 | $0 | QLD stamp duty calculator |
| Western Australia | $27,265 | $16,150 | WA stamp duty calculator |
| South Australia | $32,330 | $32,330 | SA stamp duty calculator |
| Tasmania | $26,748 | $26,748 | TAS stamp duty calculator |
| Australian Capital Territory | $17,048 | $0 | ACT stamp duty calculator |
| Northern Territory | $34,650 | $34,650 | NT stamp duty calculator |
Land titles fees to register the transfer and the mortgage come on top. Our home deposit and upfront costs calculator adds the deposit, stamp duty, titles fees and an LMI range for your price and state.
How to cut 10 years off a 30 year mortgage
Pay about $692 a month extra on a $600,000 loan at 6.23%. Repaying $4,379 instead of $3,687 clears it in 20 years and saves about $276,300 in interest. Check your loan allows extra repayments: many fixed loans cap them, and our fixed vs variable guide lists each lender's limit. Enter your own loan and an extra repayment in the calculator to see the time and interest you'd save.
Deposits, building and other questions people ask
- Is $400,000 enough to build a house? It is below the ABS's average value of a new house approved in Australia, and land is extra. See what a new house costs to build.
- How much deposit do I need for a $500,000 house? $25,000 (5%) through the 5% Deposit Scheme if you're eligible, or $100,000 (20%) to avoid LMI. See the deposit calculator.
- Can I buy a house with a $20,000 deposit? Possibly: it is 5% of a $400,000 home. See low deposit home loans.
What the calculator doesn't include
- Fees. Package, monthly and setup fees add to the cost. Compare loans on the comparison rate as well as the interest rate.
- Rate changes. Variable rates move. Check what your repayment would be at higher rates with our stress test calculator.
- Changing offset balances and redraws. The calculator holds the offset balance steady and assumes extra repayments stay in the loan.
- Lenders mortgage insurance. If LMI is added to your loan, include it in the loan amount. Our LMI calculator gives an indicative range, and low deposit loans and LMI explains how it works.
How much can I borrow on my salary?
Lenders work backwards from your income after tax, living expenses and other debts, and test the loan at your rate plus 3 percentage points. On our assumptions a single applicant needs about $148,000 a year for an $800,000 loan. The borrowing power calculator gives an indicative range for your own figures, and the stamp duty calculator shows the duty to budget for on top of your deposit.
Using a bank's rate in this calculator
Bank calculators, such as the CommBank, ANZ or Westpac mortgage repayment calculators, use the same maths. The difference is that they pre-fill the bank's own rates. To compare lenders, take each lender's rate for your LVR and loan type from its rates page and run it here with the same loan amount and term. Our lender reviews explain how each bank sets its rates and include this calculator:
Suncorp Bank customers: Suncorp Bank is no longer taking new home loan applications as its customers move to ANZ, but existing borrowers can enter their current Suncorp rate here. Its variable rates rose by 0.25% p.a. on 9 October 2026. See our Suncorp Bank review.
Mortgage repayment questions
How is a mortgage repayment calculated?
With the amortisation formula M = P × r × (1 + r)^n ÷ ((1 + r)^n − 1), where P is the loan amount, r is the interest rate per repayment period and n is the number of repayments. It gives the fixed repayment that pays the loan off exactly over the term.
How much is a $600,000 mortgage a month in Australia?
About $3,687 a month at 6.23% over 30 years (principal and interest), or $3,597 at 6.00%. Over 25 years at 6.23% it is about $3,951.
How much will I repay monthly on a $1,000,000 mortgage?
About $6,144 a month at 6.23% over 30 years, or $5,996 at 6.00%. Total interest at 6.23% over 30 years would be about $1.21 million if the rate never changed.
How do I cut 10 years off a 30 year mortgage?
Pay about $692 a month extra on a $600,000 loan at 6.23%. Repaying $4,379 instead of $3,687 clears it in 20 years and saves about $276,300 in interest, if your loan accepts extra repayments.
What is the interest-only repayment on $600,000?
$3,115 a month at 6.23%. After a five-year interest-only period the repayment rises to $3,951 to clear the loan over the remaining 25 years, against $3,687 if you'd paid principal and interest from the start.
Do fortnightly repayments save money?
Only if you pay more. A true fortnightly repayment (the annual amount split into 26) costs almost the same as monthly. Paying half your monthly repayment every fortnight means 13 monthly repayments a year, which on $500,000 at 6.00% cuts the term to about 24.5 years and saves around $124,000 in interest.
What happens if I pay an extra $100 a week?
On a $600,000 loan at 6.23% over 30 years with weekly repayments, an extra $100 a week saves about $205,063 in interest and pays the loan off 7 years and 4 months sooner, if your loan accepts extra repayments.
Does this calculator include an offset account?
Yes. Open the extra repayments, offset and interest-only options and enter your offset balance. It reduces the balance interest is charged on, so with the same repayment the loan is paid off sooner: $30,000 kept in offset on a $600,000 loan at 6.23% saves about $141,574. Fees, rate changes and lenders mortgage insurance aren't included.
How much do you need to earn for an $800,000 mortgage?
About $148,000 a year for a single applicant with no other debts and living costs of $2,500 a month, with the loan tested at 9.23% over 30 years. Use the borrowing power calculator for your own income and expenses.
Is this the same as the CommBank, ANZ or Westpac calculator?
For the same loan amount, rate, term and frequency, yes: banks use the same amortisation maths. Bank calculators often pre-fill their own rates, which is the main difference. Take the rate from the lender's rates page and enter it here.
Related tools and guides
Borrowing for something other than a home? Try the car loan calculator, the personal loan calculator or thenovated lease calculator.
