Compare fixed and variable portions of your home loan, test different split percentages, and see the effect of offset and extra repayments on the variable portion.
📖 15 min read · ⏱️ Calculator time: ~40 seconds
| Metric | Fixed portion | Variable portion |
|---|
Split loan structures, fixed-rate break costs, offset availability and extra repayment rules vary between lenders and loan products. Results are estimates only.
A split loan divides your mortgage into two (or more) portions — commonly one fixed-rate portion and one variable-rate portion — each behaving as its own separate loan with its own rate, repayment and features. Splitting is a popular middle-ground strategy for Australian borrowers who want some rate certainty without giving up all the flexibility a variable loan offers.
Each portion of a split loan amortises independently over the same overall loan term. The fixed portion locks in its rate for an agreed fixed period (commonly 1-5 years), after which it automatically reverts to a variable rate — usually your lender's standard variable rate at that time, re-amortised over your remaining term. The variable portion floats with market rates for the life of the loan and typically retains full flexibility, including offset and unlimited extra repayments.
A fixed rate gives you repayment certainty for the fixed period, protecting you from rate rises but also meaning you don't benefit if rates fall. A variable rate moves with the market — you benefit immediately from rate cuts, but also carry the risk (and uncertainty) of rate rises. Splitting your loan lets you hedge between these two outcomes rather than betting entirely on one.
Offset accounts are typically only available on the variable portion of a split loan — this is standard Australian lending practice, and the calculator above models it accordingly. Money in the offset account reduces the interest-bearing balance of the variable portion directly, which is exactly why many split-loan borrowers direct their savings toward the variable side rather than the fixed side. See our dedicated Offset Account Calculator for a deeper look at how offset accounts work.
Like offset, unlimited extra repayments are generally only available on the variable portion — fixed-rate portions commonly cap extra repayments (often around $10,000 per year) with fees or break costs if you exceed the limit. The Offset & Extra Repayment Benefit panel in the calculator above shows exactly how much interest you can save by directing extra repayments to your variable portion.
When your fixed period ends, that portion automatically reverts to a variable rate — often your lender's standard variable rate, which can be higher than the special fixed or introductory rates on offer. The Fixed Rate Expiry panel in the calculator above shows your repayment before and after this transition, so you can plan ahead rather than being caught by surprise. Many borrowers use this window to review their options — refinancing, re-fixing, or simply continuing on the new variable rate.
As your fixed period approaches expiry, it's worth comparing your options rather than automatically rolling onto your lender's standard variable rate. Use our dedicated Refinance Calculator to compare switching lenders against staying and re-fixing or moving to variable — factoring in any break costs on the fixed portion and establishment costs of a new loan.
| Scenario | Split | What to notice |
|---|---|---|
| 50/50 split | Even balance | Moderate rate certainty, moderate flexibility |
| 70/30 split | Fixed-heavy | More certainty, less flexibility from offset/extra repayments |
| 80/20 split | Fixed-heavy | Strong rate certainty, small variable portion for flexibility |
| Offset account | Any split | Applied to variable portion only — see Offset & Extra Repayment Benefit panel |
| Extra repayments | Any split | Also variable portion only — same panel |
| Investor loan | Any split | Same mechanics; consider with your accountant for deductibility |
| First-home buyer | Lower fixed % | May prefer more variable-portion flexibility while building savings |
| Refinancing | New split at new lender | Compare fixed-rate break costs against potential savings |
Enter each of these scenarios into the calculator above to see exact figures for your own loan.
| Term | Meaning |
|---|---|
| Split loan | A mortgage divided into fixed and variable portions, each behaving as its own loan. |
| Fixed rate period | The agreed term during which the fixed portion's rate is locked in. |
| Reversion rate | The variable rate a fixed portion moves to once its fixed period ends. |
| Break cost | A fee charged for exiting or restructuring a fixed-rate loan before its term ends. |
| Offset account | A linked account whose balance reduces the interest charged — typically variable-portion only in a split loan. |
| Extra repayment cap | A limit (often ~$10,000/year) on additional repayments permitted on a fixed-rate portion without fees. |
A split loan lets you hedge between the certainty of a fixed rate and the flexibility of a variable rate, rather than committing entirely to one or the other. Use the calculator above to test different split percentages, see the effect of offset and extra repayments on your variable portion, and plan ahead for when your fixed period expires. Pair it with our Refinance and Mortgage calculators for the complete picture of your loan strategy.
What is a split loan?
A split loan divides your mortgage into two portions — commonly fixed and variable rate — each behaving as its own separate loan with its own rate, repayment and features.
How does a split loan work?
Each portion amortises independently over the same loan term. The fixed portion locks in its rate for an agreed period then reverts to variable; the variable portion floats with market rates throughout, typically retaining offset and unlimited extra repayments.
What is a good split between fixed and variable?
There's no universal answer — it depends on your risk tolerance, cash flow needs, and rate outlook. Common splits are 50/50, 60/40, 70/30 and 80/20; use the Split Scenario Comparison panel above to compare your options.
Does offset apply to the whole split loan?
Generally no — offset typically only applies to the variable portion, consistent with standard Australian lending practice, which is why the calculator above models it that way.
Can I make extra repayments on a split loan?
Yes, though usually only the variable portion allows unlimited extra repayments — the fixed portion commonly caps extra repayments (often around $10,000/year) with fees or break costs if you exceed the limit.
What happens when my fixed rate expires?
That portion automatically reverts to a variable rate, re-amortised over your remaining term — often producing a different repayment than during the fixed period. See the Fixed Rate Expiry panel above.
Is a split loan better than a fully fixed or fully variable loan?
It depends on your priorities — a split loan is a middle ground, trading some flexibility for partial rate certainty. Compare all three using the 100% Fixed vs 100% Variable panel above.
What is a break cost?
A fee charged by lenders for exiting or restructuring a fixed-rate loan before its term ends, generally reflecting the lender's cost of unwinding their own funding arrangements — amounts vary significantly and depend on how far interest rates have moved.
Can I change my split percentage later?
Often yes, though this may require refinancing or restructuring, and could trigger break costs on the fixed portion — check with your lender about their specific process and any associated costs.
How is the reversion rate determined?
It's typically your lender's standard variable rate at the time your fixed period ends — this can't be known precisely in advance since it depends on market conditions at that future date. The calculator above lets you enter your own estimate.
Does a split loan cost more in fees than a standard loan?
Not necessarily — many lenders don't charge extra for a split loan structure itself, though you should confirm this and check for any package or account-keeping fees specific to your lender's split loan product.
Can investors use split loans?
Yes — the mechanics work identically for investment properties. Consider discussing the tax implications of your specific structure with a registered tax agent.
What's the maximum number of splits I can have?
Most lenders allow two splits (fixed and variable), though some offer more complex multi-way splits — this calculator models the standard two-way split, the most common structure in Australia.
Should I split my loan or keep it simple?
This is a personal decision based on your risk tolerance and how much you value certainty versus flexibility — the calculator above helps quantify the trade-off for your specific numbers, but the right choice depends on your own circumstances.
How accurate is this split loan calculator?
It uses a proper independent amortisation for each portion, including fixed-rate reversion, and has been tested against manual calculations. Actual lender terms, break costs and extra repayment rules vary — confirm exact figures with your lender.
Can I have different loan terms for each portion?
This calculator assumes both portions share the same overall loan term, which is the most common structure — some lenders may offer different term lengths per portion; check with your specific lender if this applies to you.
Does a split loan affect my borrowing capacity?
Not directly — lenders assess your overall repayment ability regardless of how the loan is structured internally, generally using the higher of the fixed or a stressed variable rate for serviceability purposes.
What is the typical fixed rate period in Australia?
Commonly 1 to 5 years, with 2-3 years being especially popular — some lenders offer longer fixed terms up to 10 years, though these are less common.
Can I pay off my fixed portion early?
Yes, but this may incur break costs, since you're ending the fixed-rate agreement before its term — confirm the exact cost with your lender before making a large extra payment on the fixed portion.
Does the variable portion have a rate cap?
No — standard variable rates aren't capped and can move with the market in either direction, which is the fundamental trade-off against the certainty of the fixed portion.
Can first home buyers benefit from a split loan?
Yes — some first home buyers prefer a smaller fixed portion for repayment certainty while keeping a larger variable portion flexible for extra repayments as their income grows.
What happens if interest rates fall during my fixed period?
Your fixed portion's repayment stays the same regardless — you won't benefit from the rate cut on that portion until your fixed period ends, though your variable portion will benefit immediately.
What happens if interest rates rise during my fixed period?
Your fixed portion is protected — its repayment stays the same throughout the fixed period, while your variable portion's repayment would rise with the market.
Is a split loan available on all mortgage products?
Most major Australian lenders offer split loan options, though specific features (offset availability, extra repayment caps, minimum split percentages) vary by lender and product — confirm with your specific lender.
Can I use a redraw facility on a split loan?
This depends on your lender and which portion — redraw is more commonly available on variable portions, similar to offset and extra repayments, though policies vary.
Does splitting my loan increase my total interest paid?
It depends entirely on how rates move over the loan's life — the 100% Fixed vs 100% Variable panel above lets you compare your specific split against both extremes using your entered rates.
Should I split evenly or favour one portion?
This depends on your priorities — a larger variable portion favours flexibility (offset, extra repayments), while a larger fixed portion favours certainty. Use the Split Scenario Comparison panel above to compare options directly.
Can I refinance just one portion of my split loan?
This is sometimes possible depending on your lender, though it may be simpler to refinance the whole loan — discuss your specific situation with a mortgage broker or your lender.
Does LMI apply differently to a split loan?
No — LMI is assessed on your total loan amount and LVR, regardless of how the loan is subsequently split between fixed and variable portions. See our dedicated LMI Calculator.
What is a fixed rate lock fee?
Some lenders charge a fee to guarantee (lock in) a fixed rate between application and settlement, protecting you if rates rise in that window — this is separate from the fixed rate itself; ask your lender if this applies.
Can I add an extra split later?
Some lenders allow restructuring into a three-way or more complex split later — this typically requires a formal request and may involve fees; check directly with your lender.
Does a split loan work the same for construction loans?
Construction loans are usually variable during the drawdown period, with splitting typically only becoming relevant once construction is complete and the loan converts to standard repayments — see our dedicated Construction Loan Calculator for the construction-specific mechanics.
What is the difference between a split loan and a basic variable loan?
A basic variable loan is 100% variable with no fixed component — you get maximum flexibility but no rate certainty. A split loan gives you a mix of both.
How do I decide my fixed rate period?
This depends on your view of where rates are heading and how much certainty you value — shorter periods (1-2 years) offer more flexibility to reassess sooner, while longer periods (3-5 years) lock in certainty for longer.
Can I export my split loan scenarios?
Yes — use the CSV button above for a comparison across common split percentages, or the PDF button for a summary report of your current scenario.
Does the calculator show a year-by-year balance?
Yes — the Combined Loan Balance chart above shows your total balance (fixed plus variable) over time, with a text summary for accessibility.
Is my repayment the same every month during the fixed period?
Yes, for the fixed portion — that's the point of fixing. Your variable portion's repayment can change if the variable rate moves, or if you adjust your extra repayments.
What if I want 100% certainty about my repayments?
A 100% fixed loan gives you full certainty for the fixed period, though it comes with less flexibility (no offset, capped extra repayments) — compare this option directly in the 100% Fixed vs 100% Variable panel above.
Can I split a construction loan?
Typically not until construction is complete, since construction loans are usually variable and interest-only during the drawdown phase — splitting usually becomes an option once the loan converts to standard principal and interest repayments.
Does a split loan help manage interest rate risk for investors?
Yes — many investors use split loans specifically to manage cash flow certainty on part of their portfolio debt while retaining flexibility on the rest, though the right structure depends on your individual investment strategy.
What should I ask my lender about a split loan?
Confirm the exact fixed rate period options available, whether offset applies to any portion, the extra repayment cap on the fixed portion, and how break costs are calculated if you need to exit early.
Does the fixed portion earn a discount for a bigger loan?
Some lenders offer tiered fixed rates based on loan size or LVR — check your specific lender's current rate card, as this varies and changes over time.
Can I use this calculator to plan around a rate rise?
Yes — adjust the variable rate input to model a rate rise and see the effect on your variable portion's repayment and the combined total, both now and after your fixed portion reverts.
Does a bigger fixed portion always mean lower risk?
It means lower interest-rate risk (less exposure to future rate rises), but it also means less flexibility from offset and extra repayments, and potentially higher total interest if variable rates end up lower over the loan's life — see the 100% Fixed vs 100% Variable panel above.
What's the difference between a split loan and a fixed loan with an offset sub-account?
A split loan divides the actual loan balance between fixed and variable rates. Some lenders offer a "100% offset on a fixed loan" style product, which is different and less common — always confirm exactly what structure and features your specific loan product offers.