Monthly vs Fortnightly vs Weekly Mortgage Repayments: Which Saves You More? (2026)
Most Australians set up their mortgage repayments and never think about the frequency again. But the payment schedule you choose — monthly, fortnightly, or weekly — can mean the difference between paying off your loan in 24 years instead of 30, and saving over $150,000 in interest along the way.
This guide compares all three repayment frequencies with real numbers, explains exactly why fortnightly and weekly payments outperform monthly, and shows you how to make the switch with your lender.
The key insight
Switching from monthly to fortnightly repayments on a $600,000 loan at 6.5% over 30 years saves approximately $179,000 in interest and cuts 6 years off your loan — with no increase in your individual payment amount.
How Mortgage Repayment Frequency Works
The mathematics behind repayment frequency are simpler than most people expect. Here's the critical point: there are 52 weeks in a year, 26 fortnights, but only 12 months. This asymmetry is the entire reason fortnightly payments outperform monthly ones.
When lenders calculate your fortnightly repayment, they typically take your monthly repayment and divide it by two. So if your monthly payment is $3,793, your fortnightly payment is $1,897. Here's where the magic happens: 26 fortnightly payments of $1,897 equals $49,322 per year, compared to 12 monthly payments of $3,793 which equals $45,516. You end up making the equivalent of 13 monthly payments per year instead of 12.
That extra month's worth of repayments goes entirely to reducing your principal, which reduces the interest charged in every subsequent period. The compounding effect of this over decades is substantial.
Weekly works on the same principle
Weekly repayments (calculated as monthly ÷ 4) result in 52 payments per year, equalling the same annual amount as fortnightly. The additional benefit of weekly comes from slightly earlier principal reductions each period — saving a small but meaningful amount of extra interest.
Monthly vs Fortnightly vs Weekly: Head-to-Head Comparison
The table below compares all three repayment frequencies for a $600,000 home loan at 6.5% per annum over 30 years — a realistic scenario for many Australian borrowers in 2026.
| Feature | Monthly | Fortnightly | Weekly |
|---|---|---|---|
| Repayment amount | $3,793/month | $1,897/fortnight | $948/week |
| Payments per year | 12 | 26 | 52 |
| Total paid per year | $45,516 | $49,322 | $49,296 |
| Effective loan term | 30 years | ~24 years | ~23.9 years |
| Total interest paid | $765,480 | ~$587,000 | ~$584,000 |
| Interest saved vs monthly | — | ~$178,000 | ~$181,000 |
| Years saved vs monthly | — | ~6 years | ~6.1 years |
Based on a $600,000 loan at 6.5% p.a. interest rate, 30-year term. Fortnightly and weekly payments calculated as monthly repayment ÷ 2 and ÷ 4 respectively. Figures are indicative estimates.
Savings by Loan Amount: Fortnightly vs Monthly
The bigger your loan, the greater the dollar savings from switching to fortnightly repayments. Here's how the numbers stack up across common Australian loan sizes at 6.5% p.a. over 30 years.
| Loan Amount | Monthly Repayment | Fortnightly Repayment | Interest Saved | Years Saved |
|---|---|---|---|---|
| $400,000 | $2,529/month | $1,265/fortnight | ~$119,000 | ~6 years |
| $500,000 | $3,161/month | $1,581/fortnight | ~$149,000 | ~6 years |
| $600,000 | $3,793/month | $1,897/fortnight | ~$178,000 | ~6 years |
| $750,000 | $4,741/month | $2,371/fortnight | ~$223,000 | ~6 years |
| $1,000,000 | $6,321/month | $3,161/fortnight | ~$297,000 | ~6 years |
Figures based on 6.5% p.a. interest rate, 30-year loan term. Fortnightly payment = monthly ÷ 2. Figures are indicative estimates — use a mortgage calculator to model your exact situation.
Each Repayment Frequency Explained
Monthly Repayments
Monthly is the traditional default. Most lenders set you up on monthly repayments unless you actively choose otherwise. You make 12 payments per year, and your loan balance reduces 12 times annually.
The advantage of monthly is simplicity — it's easy to budget around one large payment per month, and it aligns with typical billing cycles. However, you pay the most interest over the life of the loan compared to more frequent schedules.
Best for:
Borrowers paid monthly, those who prefer simplified budgeting, or anyone whose income arrives in large monthly sums (e.g. self-employed, contract workers paid on invoices).
Fortnightly Repayments
Fortnightly is the most popular accelerated repayment schedule in Australia, and for good reason. By paying every two weeks, you make 26 payments per year — the equivalent of 13 monthly payments. That extra payment goes directly toward reducing your principal each year.
Fortnightly also aligns naturally with how most Australian employees are paid (ABS data shows the majority of salaried workers are paid fortnightly or weekly). This makes budgeting easier — your mortgage comes out the same week your salary arrives.
Best for:
Most Australian borrowers — especially those paid fortnightly, anyone wanting to pay off their mortgage faster without feeling a pinch, and first home buyers looking to build equity faster.
Weekly Repayments
Weekly repayments achieve similar results to fortnightly but with smaller, more frequent payments. You make 52 payments per year — the same annual total as fortnightly, but with each payment applied to your loan one to two weeks earlier on average.
The interest saving over fortnightly is modest (typically $2,000–$5,000 over the life of a $600,000 loan) because interest on Australian home loans is calculated daily. Earlier payments reduce the daily balance slightly more, but the difference is marginal compared to the large gains already achieved by switching from monthly.
Best for:
Borrowers paid weekly, those who prefer smaller, more frequent payments for cash flow management, or anyone who wants to squeeze every last dollar of savings from their repayment schedule.
Why Fortnightly Beats Monthly: The Maths Simply Explained
The mechanism is straightforward. Here's a worked example:
Worked example: $600,000 loan at 6.5%
That extra ~$3,806 per year attacks your principal from year one, reducing the base on which all future interest is calculated. Because mortgage interest compounds daily in Australia, even small reductions in principal have outsized effects over decades.
The result: a loan that would have taken 30 years on monthly repayments is paid off in approximately 24 years on fortnightly — without the individual payment amount increasing in any meaningful way.
Watch Out: "Fortnightly" Isn't Always What It Seems
Not all lenders calculate fortnightly repayments the same way. There are two approaches, and the difference is significant:
| Method | Calculation | Annual payments | Result |
|---|---|---|---|
| "Fake" fortnightly | Annual repayment ÷ 26 | 26 × smaller amount | Same as monthly — no benefit |
| True fortnightly | Monthly repayment ÷ 2 | 26 × half-monthly amount | Extra month's payment — major savings |
The "fake fortnightly" option simply divides your annual repayment by 26, which means you're paying the exact same annual amount as monthly — just spread differently. You get no acceleration benefit.
Action step
Ask your lender explicitly: "Is my fortnightly repayment calculated as my monthly repayment divided by two?" If the answer is no, you may not be getting the full benefit. Some lenders only offer true fortnightly on variable rate loans.
Which Repayment Frequency Should You Choose?
The right choice depends on your income cycle, cash flow, and financial goals. Here's a quick decision guide:
Choose monthly if:
- You are paid monthly
- You have irregular income and prefer larger, less frequent payments
- Your budget is very tight and the equivalent of one extra monthly payment per year would cause financial stress
- Your lender doesn't offer true fortnightly repayments
Choose fortnightly if:
- You are paid fortnightly (the most common Australian pay cycle)
- You want to pay off your loan significantly faster without feeling the pinch
- You're a first home buyer looking to build equity quickly
- You want the best balance of savings and cash flow predictability
Choose weekly if:
- You are paid weekly
- You prefer smaller, more frequent payments for cash flow management
- You want to maximise savings (marginally more than fortnightly)
- You're comfortable managing your account with frequent transactions
How to Switch Your Repayment Frequency
Switching repayment frequency is generally simple and free with most Australian lenders. Here's how to do it:
- 1Log in to your lender's online portal
Most major Australian lenders (CBA, ANZ, NAB, Westpac, Macquarie, etc.) allow you to change your repayment frequency through their online banking portal or mobile app.
- 2Navigate to your home loan settings
Look for "repayment settings", "loan management", or similar. The path varies by lender, but repayment frequency is typically adjustable without needing to call anyone.
- 3Confirm the new repayment amount
Before confirming, verify that your fortnightly repayment is approximately half your monthly amount. If it's noticeably less, ask your lender to confirm the calculation method.
- 4Update your direct debit or salary credit
If you use a direct debit, update the amount and frequency. If you credit your salary directly to your mortgage offset account, no changes are needed — just ensure your salary timing aligns with when repayments are debited.
On a fixed rate loan?
Lenders often restrict repayment frequency changes on fixed rate loans. You may only be able to switch when your fixed period ends and the loan rolls to a variable rate. Check with your lender before the fixed term expires.
Should You Use an Offset Account Instead?
An offset account works by reducing the interest-bearing balance of your loan. Every dollar sitting in your offset account is a dollar on which you don't pay interest. This is a complementary strategy to repayment frequency — not an either/or.
If your employer pays your salary into your offset account and you leave it sitting there as long as possible before paying bills, you automatically reduce your loan's interest-bearing balance throughout the month. Combining an offset account with fortnightly repayments can deliver even greater savings.
The power combination
Salary credited to offset + fortnightly repayments = maximum interest reduction with no lifestyle sacrifice. Your money works for you every day it sits in the offset account, then fortnightly repayments keep accelerating the payoff.
Calculate Your Exact Savings
The figures in this guide are estimates based on typical loan scenarios. Your actual savings will depend on your loan balance, interest rate, remaining term, and your lender's specific calculation method.
Use our free mortgage repayment calculator to model your exact situation — see your monthly, fortnightly, and weekly options side by side with interest savings calculated for your specific loan.
Key Takeaways
- Fortnightly beats monthly because 26 half-monthly payments per year equals 13 monthly payments — one extra payment that accelerates principal reduction.
- Weekly vs fortnightly is a marginal difference — both result in similar annual totals. The real win comes from switching away from monthly.
- $600,000 borrowers can save approximately $178,000 in interest and 6 years of repayments by switching from monthly to fortnightly — at no increase in individual payment size.
- Check your lender's method — ensure fortnightly is calculated as monthly ÷ 2 (not annual ÷ 26) to get the full benefit.
- Switching is free for most variable rate borrowers and can be done in minutes through online banking.
Figures in this article are estimates for illustrative purposes. Individual results will vary based on loan amount, interest rate, remaining term, and lender policies. Consult a licensed mortgage broker or financial adviser for advice tailored to your situation.
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