Split Loan Calculator

Calculate your repayments and total interest when splitting your home loan between fixed and variable rates.

Total Monthly Repayment
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Weighted Average Rate
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Total Interest
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Fixed Portion Amount
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Fixed Monthly Repayment
$0
Variable Portion Amount
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Variable Monthly Repayment
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How Split Home Loans Work in Australia

A split loan divides your mortgage into two separate sub-accounts: one on a fixed interest rate and one on a variable rate. You choose what percentage goes to each portion. Both portions form part of the one mortgage against your property, but they operate with separate interest rates, repayments, and features.

Why Split Your Loan?

A split loan is the "have your cake and eat it too" approach to the fixed vs variable dilemma. The fixed portion gives you certainty — you know exactly what that repayment will be regardless of RBA rate movements. The variable portion gives you flexibility: you can make unlimited extra repayments, attach an offset account, and benefit if rates fall. Many Australian borrowers find this balance appealing, particularly when rates are uncertain.

Understanding the Weighted Average Rate

The weighted average rate shown in the results is the single effective rate across your entire loan. It's calculated as: (fixed portion × fixed rate + variable portion × variable rate) ÷ total loan. This makes it easy to compare your split loan against a single-rate product. If the weighted average rate is lower than any single-rate alternative, the split may be the better deal overall.

Choosing Your Split Ratio

The right split depends on your priorities:

  • Larger fixed portion (e.g. 70–80%): More rate certainty, stable budgeting, less interest rate risk. Better if you're on a tight budget or expect rates to rise.
  • Larger variable portion (e.g. 70–80%): More flexibility for extra repayments and offset savings. Better if you have surplus income to put to work reducing the loan.
  • 50/50: A balanced approach that many borrowers start with. Easy to understand and provides meaningful exposure to both benefits.

Offset Accounts and Split Loans

One important consideration: offset accounts typically only apply to the variable portion. Your offset savings reduce interest only on the variable sub-account. If maximising offset benefits is your goal, a larger variable portion makes sense. Use our Offset Savings Calculator to model how much your offset savings could reduce interest on the variable portion.

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Frequently Asked Questions

What is a split home loan?
A split loan divides your mortgage into a fixed rate portion and a variable rate portion. You choose the percentage allocated to each. The fixed portion gives repayment certainty; the variable portion offers flexibility such as unlimited extra repayments and offset account access.
What is the best fixed/variable split ratio?
There's no universal answer — it depends on your financial situation and goals. A 50/50 split is a common starting point. If you value certainty and are on a tight budget, lean toward a larger fixed portion. If you have surplus cash to reduce the loan and want to maximise offset savings, lean variable. Use the slider above to see how different ratios affect your repayments and interest.
Can I have an offset account on a split loan?
Generally, offset accounts are only available on the variable portion of a split loan. The fixed portion typically cannot be offset. This means that when sizing your split, the amount you plan to hold in an offset account should inform how large you make the variable portion — you want enough variable balance for the offset to have meaningful impact.
What happens if I want to change my split?
Changing the split during a fixed term is treated as breaking the fixed portion, which can trigger break costs. Once the fixed term expires, you can renegotiate or restructure without break costs. Most borrowers set their split at origination and revisit it at each fixed term renewal.
Are extra repayments allowed on a split loan?
On the variable portion, extra repayments are typically unlimited. On the fixed portion, most lenders cap extra repayments at $10,000–$20,000 per year. If you plan to make large extra repayments, keep a larger variable portion or check your lender's specific terms before committing.
Do I get two separate accounts with a split loan?
Yes. Most lenders manage fixed and variable portions as separate sub-accounts, each with their own repayment schedule, statement, and interest charge. Some lenders present these as a single loan with two components. Either way, you make separate repayments to each portion (or combined to one account, depending on the lender).
Disclaimer: This calculator provides estimates based on the rates and split ratio you enter. Actual repayments may differ based on your lender's calculation method and fee structure. Offset savings on the variable portion are not included in the interest total shown. Not financial advice.
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