Model Australian mortgage repayments, offset balances, extra repayments and total interest. Change the stated rate and assumptions; estimates are not lender quotes.
Compare weekly, fortnightly, and monthly repayments so the loan fits how you actually budget.
See how much interest builds over the life of the loan and how rate changes affect repayments.
Move from repayment estimate to borrowing power, stamp duty, LMI, refinance, or extra repayment planning.
Enter your loan amount, interest rate, and loan term to see your repayments instantly. Use the frequency toggle to switch between weekly, fortnightly, and monthly repayments. Add extra repayments to see how much time and interest you can save. Save up to three scenarios to compare side-by-side, or share your calculation with your partner or broker via a unique URL.
Mortgage repayments are useful only when they are connected to the full buying decision. Use the repayment estimate as the centre point, then check whether the loan amount is realistic, whether upfront costs fit your savings, and whether a different loan structure changes the long-term result.
A higher rate increases each repayment and total interest. A lower rate can improve cash flow, but fees and loan features still need to be compared.
Weekly and fortnightly repayments can be easier to align with pay cycles. Always compare the actual annual amount paid, not just the smaller per-period number.
Extra repayments reduce principal earlier, so future interest is charged on a smaller balance. Use the dedicated extra repayment calculator for deeper planning.
Stamp duty, LMI, conveyancing, and inspections can change how much cash is left for deposit and how much you need to borrow.
This is the minimum amount you need to pay each period to repay your loan in full by the end of your term. Your actual lender repayment may vary slightly based on fees and how your lender rounds figures.
The total amount of interest you'll pay over the life of the loan — in addition to repaying the original loan amount. For most 30-year loans, total interest exceeds the original loan amount. This is why extra repayments and a lower interest rate have such a significant impact.
The chart shows how each repayment is split between principal (reducing your loan balance) and interest (the cost of borrowing). In the early years, most of each repayment goes toward interest. As your balance reduces, more goes toward principal.
Even a small amount of extra repayment each month significantly reduces the total interest paid. Every extra dollar reduces your principal, which reduces the interest charged in every future period — the effect compounds over time.
Paying half the monthly amount every fortnight makes 26 half-payments: the equivalent of 13 monthly payments each year. That increases annual repayments compared with 12 monthly payments. An annual-budget-equivalent fortnightly amount (monthly amount × 12 ÷ 26) does not add that extra payment. Compare the payment amount, timing and lender terms rather than assuming frequency alone guarantees a saving.
Model an offset balance against repayments and total interest.
Model mortgage and offsetCompare an additional payment with your scheduled repayment.
Compare extra repaymentsKeep the deposit, duty and quoted buying costs in one budget.
Download the budget plannerCheck compulsory HELP repayments separately from mortgage amortisation.
Estimate HELP borrowing impactOnce you know the repayment, work through the next decisions in order: borrowing capacity, upfront costs, deposit risk, loan comparison, and whether buying still beats renting for your situation.
Planning a first purchase? Read the deposit and upfront-cost guide. For an existing loan, compare switching costs in the refinancing guide and use the free budget workbook to record cash requirements.
Estimate whether the loan amount is realistic for your income, expenses, and commitments.
Understand the cash needed at settlement before locking in your loan size.
See whether a smaller deposit could add Lenders Mortgage Insurance to the loan.
Compare repayments, interest, and fees before choosing a lender or product.
Estimate how much a lender may let you borrow before you choose a repayment target.
Estimate duty, concessions, and upfront costs for Australian property purchases.
Check whether a low deposit could add Lenders Mortgage Insurance to the loan.
Estimate the interest and time saved by paying more than the minimum repayment.
Compare a current loan with a new offer, including fees and break-even timing.
Compare long-term renting and buying outcomes before committing to a purchase.
Compare two home loans side-by-side using repayments, interest, and fees.
See how HECS or HELP repayments may affect home loan borrowing capacity.
Downloadable planning tools
Free spreadsheets and planners you can download and use right now — no sign-up, no email required. General information only, not financial advice.
View 12 fixed sample fortnightly payments. This CSV contains values only; editing assumptions does not recalculate it.
Buyers learning how interest and principal change across a repayment schedule.
Professional XLSX workbook with budget planner, savings tracker, and instructions. Plan deposit, stamp duty, LMI, inspections, moving costs, and settlement cash.
First home buyers preparing a realistic purchase budget.
An offset account is a transaction account linked directly to your home loan. The balance sitting in the offset is subtracted from your loan balance each day before interest is calculated. With a 100% offset, an illustrative $650,000 loan and $50,000 offset balance leave $600,000 subject to interest while those balances remain unchanged. The repayment amount you make stays the same, but a larger share goes to principal, so the loan shrinks faster.
Offset availability, fees and the percentage of the balance that offsets interest depend on the loan product. Compare the total cost with a loan without an offset and check access conditions. Calcy does not assume an offset is best for everyone.
Choose a starting offset balance that reflects your own savings and planned withdrawals. The model uses your inputs; it does not estimate a typical household balance or rely on claimed broker conversations.
The "Add an offset account" toggle on this calculator models exactly that dynamic month by month. Enter your starting balance and how much you can add each month from leftover income — the calculator will show the years shaved off your loan, the total interest saved, and the effective rate you're really paying once the offset is taken into account.
Calcy uses the standard amortising loan approach: the loan amount, interest rate, loan term, repayment frequency, and any extra repayments are combined to estimate the repayment required to reduce the balance over time.
In plain English, each repayment is split into interest and principal. Interest is the cost of borrowing for that period. Principal is the part that reduces the loan balance. As the balance falls, less interest is charged and more of each repayment goes toward principal.
Offset and extra repayment options are modelled as repayment scenarios inside the calculator. They are estimates for planning, not lender quotes or financial advice.
Compare the entered rate and fees with a current lender quote. Check state duty and first-home eligibility separately, and allow for expenses beyond repayments. If you find an outdated figure or calculation issue, use our Contact page and include the page URL and the source you believe should be reviewed.
Your monthly repayment is only part of the picture. Stamp duty, LMI, and your borrowing capacity together determine the loan amount you should plug into this calculator.
Planning a first purchase? Read the deposit and upfront-cost guide. For an existing loan, compare switching costs in the refinancing guide and use the free budget workbook to record cash requirements.
Estimate state stamp duty and check first home buyer eligibility before locking in a loan amount.
If your deposit is below 20%, estimate Lenders Mortgage Insurance — often capitalised on top of your loan.
Explore a modelled repayment budget from your income and expenses; obtain a separate lender assessment.
Compare two home loans side-by-side, including fees, to find the cheaper option.
Keep a transparent schedule in the free mortgage repayment spreadsheet, or compare cash held against the loan in the illustrative offset account planner.
For an illustrative $650,000 loan at 6.39% over 30 years: $4,061.53 monthly, or equivalent annual-budget amounts of $1,874.55 fortnightly and $937.28 weekly. Interest is about $812,152 if the rate stays fixed; fees are excluded.
Type the amount you plan to borrow in Australian dollars.
Add your lender's advertised annual interest rate as a percentage.
Select the loan term in years (typically 25 or 30 years in Australia).
Switch between monthly, fortnightly or weekly to compare repayments.
Check the amortisation table to see principal vs. interest over time.
Calcy does not publish a verified current national average repayment. Use the monthly repayment calculator with your own loan amount, mortgage interest rate and remaining term; an average loan size cannot determine your repayment.
The RBA cash rate is 4.60%, effective 30 September 2026 and checked on 14 October 2026. It influences variable home loan pricing, but your lender sets your actual rate.
Halving a monthly repayment and paying it every two weeks produces 26 half-payments, equivalent to 13 monthly payments per year. That is an extra payment strategy. Calcy also shows annual-budget equivalents of monthly amounts; those equivalents do not by themselves create an extra payment. Confirm your lender's schedule.
Lender's Mortgage Insurance (LMI) protects the lender if you default. It may be required when your deposit is less than 20% of the property value (LVR above 80%). LMI can add thousands to your upfront costs but allows you to buy with a smaller deposit.
Extra repayments reduce principal and can reduce interest when permitted by your loan terms. Fixed-rate and variable-rate products have different limits and fees. Check your contract before making extra repayments.
An amortisation schedule shows how each repayment is split between interest and principal over the life of your loan. In the early years, most of each repayment is interest. By the final years, nearly all of it reduces your principal.
A $650,000 mortgage amortised over 30 years is scheduled to finish in 30 years if the assumed rate and payments stay unchanged. The effect of fortnightly instead of monthly repayments depends on the amount paid, not just the frequency. Model extra repayments separately.
An offset account reduces the balance used to calculate interest while keeping savings in a separate account. Direct extra repayments reduce principal; access through redraw depends on lender terms. Compare fees, rates, access conditions and your needs using offset account modeling. Neither option is universally better.
Use the offset modeller with a $650,000 loan, an assumed 6.14% rate, your term and planned offset balances. Savings depend on the timing of deposits and withdrawals, loan fees and lender rules. Calcy's model is an estimate, not a quote from any bank or broker.
No. Your contractual monthly P&I repayment stays the same. The offset reduces the interest portion of each repayment so a larger share goes to principal — that is why the loan is paid off sooner. The 'effective rate' figure shown next to the offset result is your headline rate weighted by the average offset position over the life of the loan.
No. An offset is a separate account that reduces the loan balance on which interest is charged. Redraw provides access to eligible extra repayments subject to lender terms. Fees, access rules and tax consequences can differ; obtain advice about your circumstances before changing how borrowed funds are used.
RBA Cash Rate — Reserve Bank of Australia — 30 Sep 2026 (checked 14 Oct 2026)
General information and estimates, not personal financial advice. Check assumptions and official sources before making decisions.