FunanceIt remembers the rate you agreed at
Set your partner's contribution as a fixed amount and record the home loan rate at the time. Funance keeps both, so every comparison is against what you actually agreed.
Mortgage splits for Australian couplesRates moved. Did the contribution?
Plenty of couples settle on a number once: you cover this much, I cover the rest. Then the RBA moves, the repayment goes up, and the agreed transfer stays exactly where it was. This works out what the same share costs now.
14 days of Pro free, no card · then the free plan, or $79 a year · no bank login
Their like-for-like contribution
$2,207/mo
+$257 a month on $1,950, so they still cover 50% of the repayment as it moves from 5.63% to 6.88%.
- Repayment when agreed (5.63%)
- $3,907
- Repayment now (6.88%)
- $4,420
- Change a month
- +$513
- Their share (50%)
- +$257
- Your share (50%)
- +$257
- Like-for-like contribution
- $2,207
At the old amount you are covering the whole $513 rise yourself. Their 50% share is $257 a month, or $3,084 a year. If rates went up a while ago, that gap has been there every month since.
Get the RBA decision by email
Subscribe for a short note when the RBA moves, with what it does to a typical repayment. Confirmed opt-in, a couple of emails a month at most. Nothing you typed above ever leaves your browser.
It is a very ordinary way for a mortgage to get lopsided without anyone deciding it should. The repayment comes out of one partner's account. The other transfers a fixed amount each month, agreed when the rate was lower. Every rise since has landed on whoever owns the account the repayment comes out of.
The RBA raised the cash rate to 4.85% on 3 November, its fifth rise in 2026 and 1.25 percentage points in all. Passed on in full, that is about $513 a month more on a $650,000 loan with 27 years left. Split half each, about $257 of that is your partner's. If the transfer has not moved, you have been covering it.
Like-for-like is the fair starting point, not the only answer. The calculator keeps their share of the repayment where it was when you agreed it and changes nothing else. Whether you settle up for the months already gone, or change the split itself, is a conversation rather than a formula.
It works in both directions. The next RBA decision is at 2:30pm on Tuesday 8 December, and if rates come down, the same share is a smaller transfer.
| Rate | Repayment, and each partner's extra |
|---|---|
| 5.63%, when agreed | About $3,907 |
| 5.88%, one rise | About $4,007, +$50 each |
| 6.13%, two rises | About $4,109, +$101 each |
| 6.38%, three rises | About $4,211, +$152 each |
| 6.63%, four rises | About $4,315, +$204 each |
| 6.88%, five rises | About $4,420, +$257 each |
| A $1,950 transfer, like-for-like | About $2,207 a month |
$650,000 over 27 years, agreed at 5.63% and split half each, with each 0.25% rise passed on in full. Illustrative principal and interest figures, not a quote.
See it with your own numbers
Every account starts with 14 days of Pro, no card. Keep it for $79 a year, or carry on with the free plan.
How it works
How Funance keeps it fair in the app
It notices when the rate moves
Update the rate on your mortgage and the Overview flags the gap: the repayment before and after, their share of the difference, and the like-for-like amount.
One tap either way
Update to the new amount, or keep the old one on purpose. Either way today's rate becomes the new starting point, so it does not keep asking about the same move.
Or let the bills set it
Rather not agree a number at all? Funance can work out their contribution from the bills you mark as shared, so it follows the mortgage repayment whenever you update it.
What you need to enter
- What your partner transfers now
- Your loan balance and years left
- The rate when you agreed the amount, and the rate now
- How you split the mortgage: half each, by income or a set percentage
Questions
Before you start
What does like-for-like mean here?
Your partner keeps paying the same share of the repayment they paid when you agreed the amount. If they cover half and the repayment goes up $513 a month, their transfer goes up about $257. Nothing else about the arrangement changes.
Should we split the mortgage by income or half each?
Both are common and neither is right for every couple. Splitting by take-home pay means you each put in the same proportion of what you earn. Half each is simpler and suits couples on similar pay. The calculator does both, so you can see the difference between them.
What if their transfer covers more than the mortgage?
Put in the whole transfer. The calculator only changes it by their share of the change in the mortgage repayment, so the groceries, bills and everything else in it stay as they were.
Why does it use today's balance for both rates?
So the answer shows the rate change and nothing else. Working both repayments on the loan as it stands today, over the same remaining term, means the rate is the only thing that differs between them.
Are the figures exact?
They are estimates calculated from the balance, rates and term you enter, using standard principal and interest amortisation. Your lender's figure may differ slightly with fees, rounding and your repayment cycle, so treat these as planning numbers rather than a quote.
Is anything I type saved or sent anywhere?
No. The calculator runs in your browser and nothing you type leaves it. The only thing the page ever sends is an email address, and only if you choose to subscribe.
Related
Related tools and guides
Mortgage scenario calculator
A repayment calculator tells you what you owe today. A scenario engine tells you what happens if the RBA moves, if you put an extra $200 a month in, or if you refinance. Those are the questions that actually change decisions.
Mortgage rate rise calculator →Budget planner Australia
Put in your pay and your bills. See what is really left in each of the next twelve months, including the ones where rego, insurance and the water bill all land at once.
Budget planner for Australians →Home equity calculator Australia
Equity is your property's value minus what you owe. Usable equity is a smaller number, and it is the one lenders care about. Confusing the two is how people end up disappointed at the bank.
Home equity calculator →Know where your money goes.
Know where you're going.
Every account starts with 14 days of Pro, no card needed. Keep it for $79 a year, or carry on with the free plan: Overview, Budget and Debts, for good. No bank login either way.
14 days of Pro free, no card · then the free plan, or $79 a year · no bank login