Weekly, Fortnightly or Monthly Repayments: Which Actually Pays Your Mortgage Off Faster?

Ask around and you will be told that switching to fortnightly repayments knocks years off your mortgage. It is one of the most repeated pieces of advice in Australian home lending, and it is almost right.

The catch is that it only works if you switch a particular way. Do it the way most lenders and most calculators will show you, and you will save around two thousand dollars over thirty years. Do it the other way, and you will save more than a hundred and seventy thousand.

Same loan. Same interest rate. Same word on the form. The difference is a single decision about the size of each payment, and almost nobody has it explained to them.

Why Fortnightly Can Help At All

The whole thing rests on a quirk of the calendar.

There are twelve months in a year, but 26 fortnights — because 52 weeks divided by two is 26, not 24. Two extra fortnights are hiding in there.

So if you take your monthly repayment, halve it, and pay that every fortnight, you do not pay twelve monthly repayments a year. You pay the equivalent of thirteen. That thirteenth payment is pure extra, and because your loan has no idea what month it is, every dollar of it comes straight off the principal.

Weekly works identically. A quarter of the monthly repayment, 52 times a year, is also thirteen months’ worth.

The Version That Does Almost Nothing

Here is where it goes wrong for most people.

When you ask a lender to switch you to fortnightly, or when you tick “fortnightly” in a repayment calculator, you will usually be given the true fortnightly equivalent: your annual repayment total divided by 26.

On a $700,000 loan at 6.00 per cent over 30 years, the monthly repayment is $4,196.85. The true fortnightly equivalent is $1,937.01 — that is $4,196.85 × 12 ÷ 26.

Notice that $1,937.01 is less than half of $4,196.85. That is the giveaway. You are paying exactly the same amount per year as before, just sliced into 26 pieces instead of 12. There is no thirteenth payment, because the arithmetic has quietly removed it.

You are not paying a cent more, so the loan does not finish appreciably sooner.

It is not literally nothing

To be precise, and this is a point most articles get wrong in one direction or the other: paying the true equivalent fortnightly does save a small amount. Interest is charged on your outstanding balance, and paying in smaller, more frequent instalments drops that balance slightly sooner within each month.

On our $700,000 example that is worth about $2,026 across thirty years, and the loan still runs the full term. Genuine, but not the transformation the advice promises. Weekly does slightly better again, at roughly $2,895, for the same reason.

The Version That Works

Instead of accepting the equivalent, pay exactly half your monthly repayment every fortnight. On our example that is $2,098.43, not $1,937.01.

The difference is $161.42 a fortnight. Over a year it adds up to about $4,197 — one extra monthly repayment, which is precisely the point.

Here is what the five schedules do to the same loan:

Read the last two columns together. For an extra $4,197 a year — about $80 a week — the loan finishes five and a half years early and costs $173,684 less in interest.

That is the entire trick. It was never really about fortnights. It was about paying one extra monthly repayment a year, and the fortnightly cycle is simply a painless way to smuggle it into your budget.

Try It On Your Own Loan

The example above is a round number. Yours will not be, and the gap between the two fortnightly options widens as the loan grows. Put your own figures in:

If you want to look at the loan from other angles — the total interest, the amortisation schedule, what a rate change does — our full loan repayment calculator covers that, and the guide to reading it explains what each output is telling you.

Weekly or Fortnightly?

As the table shows, the difference between the two accelerated options is trivial — under $800 across the life of the loan. Both deliver the same thirteen months’ worth of repayments a year.

So choose on cash flow, not on maths. Match your repayment cycle to your pay cycle. If you are paid fortnightly, fortnightly repayments mean the money leaves your account shortly after it arrives, which is far easier to sustain than watching a balance for three weeks. If you are paid weekly, pay weekly.

The best schedule is the one you will not quietly abandon in eight months.

Five Things To Check Before You Switch

1. Ask how your lender calculates it. This is the whole article in one question. Ask directly: “Will my fortnightly repayment be half my monthly repayment, or my annual total divided by 26?” If it is the second, ask whether you can nominate the higher amount instead. Many lenders will let you; some will not.
2. Check there is no fee. Changing frequency should be free. Occasionally it is bundled into a broader variation request that is not.
3. Confirm your minimum is still met. If your lender treats the true equivalent as the required minimum, paying more is simply an extra repayment — fine on a variable loan, but see the next point.
4. Watch the caps on a fixed loan. Most fixed loans limit extra repayments, commonly $10,000 to $30,000 a year. An extra $4,197 sits inside that, but check it before you commit. Our guide to fixed versus variable covers the other restrictions that come with fixing.
5. Consider an offset account instead. If your income is irregular, holding the extra in an offset account gives you the same interest reduction while keeping the money reachable. Less disciplined, more flexible.

Does This Still Work When Rates Move?

Yes, and arguably it matters more. The table assumes 6.00 per cent for thirty years, which will not happen. Every figure here is an illustration, not a forecast.

But the mechanism does not depend on the rate. Paying thirteen months’ worth instead of twelve reduces the principal faster whatever the rate is doing, and the higher the rate, the more each dollar of early principal reduction is worth. If you want context on where rates are sitting, our cash rate update covers the current position.

One practical note: when rates rise, your lender recalculates the minimum. If you are on an accelerated schedule, check that your payment has been adjusted to half the new monthly figure, not left at the old amount.

The Honest Summary

Fortnightly repayments are not magic, and the way the switch is usually made captures almost none of the benefit. The saving comes from one extra repayment a year, and if your lender hands you the true equivalent, there is no extra repayment.

Ask the question. Get the higher amount. On a typical Newcastle mortgage it is worth more than a hundred and seventy thousand dollars, and it costs about eighty dollars a week.

If you are not sure which version you are currently on, dig out your loan statement and compare your repayment to half your old monthly figure. If it is lower, you are on the equivalent — and a phone call is probably the highest-value thing you will do this month.

Want to talk through what this means for your situation? Call David on 0417 676 191 or get in touch via our contact form.

This article is general information only and does not take into account your objectives, financial situation or needs. Figures are illustrative and current as at the date of publication. Interest rates, lender policies and government scheme rules change — please seek advice specific to your circumstances before acting.