Mortgage Refinance Calculator

Work out what switching your home loan would actually save you, after the costs of switching are taken off. Enter your current balance, rate and years remaining, then the rate you have been offered.

Want a more accurate result?

Calculator results are estimates only. A personalised review can confirm your exact numbers, fees, and any available exemptions.
No fee from us for arranging your finance. No obligation. Takes 2 minutes

What this calculator works out

A lower rate on its own does not mean you are better off. Switching has upfront costs, and a new loan often comes with a longer term. This tool puts all three moving parts in one place.

Your new repayment

What you would pay each month on the new rate, and the difference against what you pay now. Check whether the calculator is using the same number of years you have left, not a fresh 30-year term.

Your break-even point

How many months of lower repayments it takes to pay back what the switch cost you. If you might sell or move before that point, the switch has not paid for itself.

Total interest over the loan

The number that actually matters. A lower monthly repayment can still mean far more interest paid overall if the term gets longer. This is where most refinancing decisions go wrong.

How the maths works

Step 1. The repayment on each loan

Both the loan you have and the loan you are considering use the standard amortising repayment formula:
P = L × i ÷ (1 − (1 + i)−n)

P is the repayment each period.
L is the balance still owing.
i is the annual rate divided by the number of repayments per year.
n is the number of repayments left.
On a monthly loan, i is the annual rate divided by 12 and n is the number of months remaining. Total interest over the loan is simply P × n − L.

Step 2. Your break-even point

Break-even months = total switching costs ÷ monthly saving
This is the single most useful number on the page. It tells you how long you need to keep the new loan before the switch has paid for itself.

One detail worth knowing about how ASIC’s own calculator handles this: upfront fees are added to the loan balance at the start rather than paid separately. That is a reasonable assumption if you roll the costs into the new loan, but it slightly changes the result compared with paying them from savings. Full assumptions are published on the Moneysmart mortgage switching calculator page.

What the formula cannot see

Every calculator assumes the rate you enter stays put for the whole term. Real variable rates move. It also assumes you make exactly the minimum repayment, ignores any offset balance, and cannot know whether a lender will actually approve you at the rate you were quoted. Treat the output as a comparison between two scenarios, not a forecast.

What switching actually costs in South Australia

Most refinance guides quote New South Wales figures. South Australian charges are different, and they are set by the Registrar-General under South Australian law, not by your lender. There are two of them, not one: your old lender’s mortgage has to come off the title, and the new lender’s has to go on.

Discharge fee, from your current lender

Commonly in the range of $150 to $400, set by each lender individually and written into your original loan contract. It covers the admin of closing the loan out. Your lender will confirm the exact figure when you request a payout.

Two government title fees

One to discharge the old mortgage and one to register the new one. Both are set by the Registrar-General, reviewed every financial year, and they are the part people forget to budget for. Work out the current amount with the Lands Titles Office fee calculator, which is the official South Australian government tool.

New loan setup fees

Application, valuation and settlement fees on the incoming loan. Many lenders waive some or all of these on a refinance to win the business, but not all do, and a waiver is often conditional. Worth asking about explicitly rather than assuming.

The two that can dwarf the rest

Break costs if you exit a fixed rate before the fixed term ends. These are not a flat fee. They depend on your balance, how long is left on the fix, and how wholesale rates have moved since. Only your lender can quote the figure, and the quote usually holds for a couple of days.

Lenders Mortgage Insurance can be triggered again if your loan is above 80 per cent of the property value. LMI already paid is generally not transferable to a new lender.

A worked example, start to finish

The figures below are illustrative and are not a rate offer, a quote, or a prediction. They exist to show how the arithmetic behaves. Your own numbers will differ.

Take a household in Adelaide’s northern suburbs with $480,000 still owing and 22 years left to run. Assume the loan is on 6.30 per cent and another lender has offered 5.85 per cent.
Step 1, the two repayments
Staying put at 6.30 per cent over 22 years: about $3,364 a month.
Switching to 5.85 per cent over the same 22 years: about $3,236 a month.
Monthly difference: $128.

Step 2, the switching costs
Assume a $350 discharge fee, plus the two South Australian title fees, and the new lender waives its application fee. Call it roughly $750 all up.

Step 3, the break-even
$750 ÷ $128 = about 6 months. After half a year the switch has paid for itself.

Step 4, the number that matters
Total interest staying put: about $408,000.
Total interest after switching: about $374,000.
Difference over the life of the loan: roughly $34,000.

The trap: resetting the clock

Here is the part that catches people, and it is the reason we built this section.

When you refinance, the new lender will usually offer you a fresh 30-year term by default. Take the same household above. Same new rate of 5.85 per cent, but the term resets from 22 years back to 30.

The monthly repayment drops to about $2,832. That is $533 a month better than what they pay now, more than four times the saving from the rate cut alone. It looks like a much better deal.

It is not. Total interest over that 30-year loan comes to roughly $539,000, against $374,000 if they had kept the 22-year term at the same rate.

Resetting the clock costs about $165,000 in extra interest, in exchange for a lower monthly figure. The rate cut saved $34,000. The term reset gave back nearly five times that.
There are situations where stretching the term is exactly the right call, for example if cash flow is genuinely tight and breathing room matters more than long-run cost. The point is not that a longer term is always wrong. The point is that it should be a decision you make on purpose, with the interest figure in front of you, rather than a default you inherit because nobody mentioned it.

When refinancing does not stack up

Plenty of pages will tell you when to refinance. Fewer will tell you when not to. These are the situations where the numbers usually say stay put.

The gap is under about 0.15 per cent

On a $480,000 balance, a 0.05 per cent cut saves roughly $14 a month and takes over four years to repay $750 of costs. A 0.20 per cent cut saves about $57 a month and breaks even in around 13 months. Where the gap is under roughly 0.15 per cent, the arithmetic takes a long time to repay the switching costs, so the rest of the loan has to be doing the work.

You might sell within the break-even window

If the break-even is 18 months and there is a realistic chance of moving, upsizing or relocating inside two years, you would pay the switching costs and never recover them. Work out the break-even first, then ask honestly how long you will hold the loan.

Your equity has gone backwards

If a new valuation puts your loan above 80 per cent of the property value, a new lender may require Lenders Mortgage Insurance even though you paid it once already. That premium can wipe out several years of rate savings on its own. Worth checking your likely valuation before applying anywhere.

The cashback is doing the persuading

A cash incentive is real money, but it is paid once and the rate applies for years. ASIC’s guidance on switching makes the same point: do the maths to check a cashback still leaves you ahead once the rate and fees are counted. Run the comparison with the cashback removed. If the loan only wins because of the cash, it is not the better loan.

What to check before you apply

Asking your current lender first

This one costs nothing, and most people skip it. ASIC’s Moneysmart guidance says it plainly: tell your existing lender you are looking at a cheaper loan elsewhere, and they may reduce your rate to keep you. If you hold at least 20 per cent equity you have more to bargain with. A repricing costs nothing, takes a phone call, and has no discharge fee, no title fees and no new application.

If they match or come close, you have saved yourself the entire switching cost. If they will not move, you now have a real number to compare against.

The five figures the calculator needs

Current balance
Years remaining
Your exact rate
Fixed or variable
Your discharge fee
All five are on your most recent loan statement or in your lender’s app. The discharge fee is in your original loan contract. If your loan is fixed, ring your lender and ask for a break cost quote before you go any further, because that single number decides the whole question.

One option: keep the repayment where it is

Where the household budget allows it, some borrowers set the new loan’s repayment to whatever they were paying before rather than dropping to the new minimum. In the example above that means paying $3,364 instead of $3,236. The extra $128 goes straight against the principal every month, which shortens the loan and compounds the benefit of the lower rate instead of quietly absorbing it.

It is the same money you were already used to paying. You just keep the benefit rather than spending it.
Related tools on this site: loan repayment calculator, borrowing power calculator and extra repayment calculator. If refinancing is about consolidating other debts rather than the rate alone, start with refinancing and debt consolidation.
Sources
Australian Government, ASIC Moneysmart: Switching home loans and Mortgage switching calculator, including the assumptions ASIC publishes for that calculator.
Government of South Australia, Office of the Registrar-General: Fees and charges, and the Lands Titles Office fee calculator. The Registrar-General sets these fees; Land Services SA collects them as the contracted service provider.

About the figures on this page. The repayment and interest amounts in the worked example were calculated directly from the formula shown above, not taken from a third party. The rates used are illustrative and are not an offer. Fee ranges are indicative of what lenders commonly charge and are not quotes; your lender and the Lands Titles Office give the exact figures for your situation.

General information only. Nothing on this page takes your objectives, financial situation or needs into account, and it is not a recommendation to switch or to stay. Whether refinancing suits you depends on facts this page cannot know. Loanity is a credit representative and can provide credit assistance once we understand your circumstances.

Don’t worry, we got your back every step of the way

Live Human Support

24/7

Talk to a real person about your numbers. Send us a message any time and we will come back to you.

Up to and over

+100

Free accessible videos, articles, and tools which we have prepared for you to ease your journey

30 Minute Consultation

For Free!

Bring your calculator result and we will check it against real lender pricing and your actual switching costs.
STILL GOT QUESTIONS?

Refinancing questions, answered

How much does it cost to refinance a home loan in Australia?

For a standard owner-occupier switching between variable loans, the upfront cost is usually a few hundred to around fifteen hundred dollars. That is made up of your old lender’s discharge fee, two government title fees, and any setup fee on the new loan that is not waived. Two things can push it much higher: break costs if you are leaving a fixed rate early, and a new Lenders Mortgage Insurance premium if your loan sits above 80 per cent of the property value. Both need to be checked before you go anywhere near an application.

Work out your repayment on both rates over the SAME number of years you have left, take the difference, then divide your total switching costs by that monthly difference. The answer is how many months until the switch pays for itself. Then check one more number: total interest over the whole loan, not just the monthly repayment. If the new loan runs longer, the monthly figure can improve while the total cost gets much worse.

There is no universal threshold, because it depends on your balance. The bigger the loan, the smaller the rate gap needs to be. On a $480,000 balance with 22 years left, a 0.20 per cent cut saves roughly $57 a month and repays about $750 of switching costs in around 13 months. A 0.05 per cent cut saves about $14 a month and takes more than four years. Under roughly 0.15 per cent the switching costs take a long time to come back, so whether it makes sense usually turns on something other than the rate, such as whether an offset account would actually be used.

It will if you let it. Most lenders offer a fresh 30-year term by default, and you can usually ask for a term that matches what you have left instead. This matters more than the rate for many borrowers. On a $480,000 balance with 22 years remaining, resetting to 30 years at the same new rate lowers the monthly repayment by a few hundred dollars but adds roughly $165,000 in total interest. Ask the lender explicitly what term the offer is based on, and ask what the repayment would be over your remaining term instead.

You can, but there may be a break cost, and it is not a fixed fee you can look up. It depends on your balance, how much of the fixed term is left, and how wholesale funding rates have moved since you locked in. If rates have risen since you fixed, the break cost can be near zero. If they have fallen, it can run into five figures. Only your lender can give you the exact number, and the quote is usually valid for a couple of business days. Get that figure first, because it decides everything else.

Yes, and ASIC’s Moneysmart guidance recommends exactly that. Tell your existing lender you are looking at a cheaper loan somewhere else. Keeping you costs them far less than winning a new customer, so many will reduce the rate rather than lose the loan. If you hold at least 20 per cent equity you have more to negotiate with. A repricing has no discharge fee, no title fees and no application, so if it works you keep the saving without paying anything for it.

That depends on the lender’s assessment queue, how complete the application is, and how quickly the two lenders coordinate the discharge and the new registration at settlement. We will not quote you a number we do not control. What we can tell you is what your chosen lender is currently indicating, and we handle the preparation and the follow-up so the application is not sitting there waiting on a missing document.

A formal application involves a credit enquiry, and enquiries are recorded on your credit file. One enquiry is normal and expected. Several enquiries in a short period, which is what happens if you apply to lender after lender hoping one says yes, is what causes problems. This is the main practical argument for working out which lender’s policy actually fits your situation before applying rather than after.

Often yes, if the property has grown in value and your income supports the larger loan. Lenders will want to know what the funds are for, and the answer affects both approval and pricing. Bear in mind that this calculator compares two loans of the same size. If you are also increasing the balance, the repayment comparison changes and the honest question becomes what the extra borrowing costs you over the remaining term, not just whether the rate is lower.

We do not charge you a fee for arranging your refinance. Brokers are generally paid a commission by the lender when the loan settles. Separately, the lenders themselves may charge discharge, application or settlement fees, and the state government charges its title fees. Those are not ours, and they are disclosed to you before you commit to anything. If any fee from us would ever apply to your situation, you would be told in writing before you proceeded.