Split Loan Calculator
Want a more accurate result?
A $600,000 split loan, four numbers
What this calculator works out
Repayment on each part
Repayment before and after
Interest against variable only
How is a split loan worked out?
As a check, take $500,000 split 50/50, with the fixed part at 6.9 per cent for three years, the variable part at 6.2 per cent and a 30 year term. The calculator returns $1,646.50 on the fixed part and $1,531.17 on the variable part, $3,177.67 a month in all. After three years the total becomes $3,069.45 and the interest over the whole loan is $608,899, against $602,444 for a variable-only loan.
= B x r / (1 – (1 + r)^-n)
Where B is the balance of that part, r is its annual rate divided by 12 and n is the number of months left. The fixed part is recalculated at the variable rate when the fixed period ends.
First, when the fixed and variable rates are the same, a split changes nothing. The default figures, $250,000 at 5.5 per cent on both parts, give $261,010 in interest whether the loan is split or not.
Second, the calculator keeps the variable rate fixed for the whole term. A split loan is useful because that rate will move, and the calculator cannot show it. The table on this page does.
Interest in the first three years on a $600,000 loan
| Variable rate after 12 months | All variable | 50/50 split | All fixed for 3 years |
|---|---|---|---|
| Falls 1 point to 5.2% | $97,757 | $104,588 | $111,419 |
| Stays at 6.2% | $109,615 | $110,517 | $111,419 |
| Rises 1 point to 7.2% | $121,501 | $116,460 | $111,419 |
| Rises 2 points to 8.2% | $133,408 | $122,413 | $111,419 |
Worked example: the variable rate rises 1 point after a year
$4,064
$3,889
What the calculator does not show you
The variable rate will move
Fixed and variable rates swap places
Break costs and extra repayment limits
Offset and redraw sit on the variable part
Before you choose a split
1
Find what you can afford if rates rise
2
Compare several splits
3
Check the contract terms
Related tools and sources
If your fixed period is about to end, see refinancing your home loan, or home loans in Adelaide if you are buying.
Reserve Bank of Australia: Statistical Table F6, Housing Lending Rates, for the August 2026 average rates on new owner-occupier loans, 6.2 per cent variable and 6.3 per cent fixed for three years or less; and Table F5, Indicator Lending Rates, for the bank indicator rates at 30 September 2026: three year fixed 7.02 per cent against 6.80 per cent for discounted variable, and 5.52 against 6.05 per cent a year earlier.
Moneysmart: Switching home loans, on break costs and other costs of leaving a loan.
About the figures. Every figure on this page was calculated with the standard monthly amortisation method, with the fixed part moving to the variable rate when the fixed period ends. The same method reproduces the calculator’s own results. The variable rate change in the table is applied after 12 months and repayments are recalculated when it changes. Rates are illustrative and are not an offer. Last updated 21 October 2026.
General information only. Nothing on this page takes your objectives, financial situation or needs into account. Your loan contract sets out the break costs, extra repayment limits and fees that apply. Loanity is a credit representative and can provide credit assistance once we understand your situation.
Split loan questions, answered
What is a split home loan?
A home loan divided into two or more parts, usually one on a fixed rate and one on a variable rate. You choose how much goes in each part, the fixed part is locked for a set number of years, and the variable part moves with the lender’s rate.
How do I work out the repayments on a split loan?
Work out each part separately, with its own balance, rate and term, and add them. On $500,000 split 50/50 at 6.9 and 6.2 per cent over 30 years, the parts are $1,646.50 and $1,531.17, which is $3,177.67 a month. The calculator above does the same for your numbers.
What happens when the fixed period ends?
The fixed balance moves to your lender’s variable rate, unless you choose to fix again, and the repayment is recalculated over the remaining term. In the $500,000 example the total repayment falls from $3,177.67 to $3,069.45 because the fixed rate was higher than the variable rate.
Does a split loan cost more than a variable loan?
It depends on where the variable rate goes. On $600,000, with the variable rate unchanged, a 50/50 split costs about $902 more in interest over three years than a variable loan. If the variable rate rises 1 point after a year, the split saves about $5,041. If it falls 1 point, it costs about $6,831 more.
What split ratio should I choose?
There is no right ratio, because it depends on how much a repayment rise would strain your budget, how long you plan to keep the loan and how much flexibility you want. A bigger fixed part gives more certainty, and a bigger variable part gives more room for extra repayments. We run your numbers at several splits so you can see the difference.
Can I make extra repayments on a split loan?
Usually on the variable part, without limit, and often with redraw. Many lenders limit extra repayments on the fixed part during the fixed period. The limit and the penalty for going over it are in your loan contract.
Can I have an offset account on a split loan?
Often only on the variable part, although the rules differ by lender and product. An offset reduces the interest charged on the variable balance, so the more of the loan that is variable, the more an offset can do.
Is a split loan better when rates are rising or falling?
It softens both. When rates rise, the fixed part shields you from some of the increase. When rates fall, you keep part of the benefit. On the $600,000 example a 1 point rise adds $195 a month on a 50/50 split against $389 on a variable loan.
Can I refinance a split loan?
Yes. The variable part can usually move at any time. The fixed part can carry a break cost if you leave before the fixed period ends, and the cost depends on market rates when you exit. Check the cost before you switch, or wait for the fixed period to end.
Why does the calculator show the same interest as a variable-only loan?
Because the fixed and variable rates are the same. If both parts are at 5.5 per cent, the split makes no difference to the interest. Change the fixed rate and the two totals separate, as they do at 6.9 and 6.2 per cent.