Fixed vs Variable Home Loan Rates

Most guides describe fixed rates as "certainty" and variable rates as "flexibility." That is true, but it skips the mechanics that actually drive pricing — and understanding the mechanics is how you spot genuine opportunities.

Variable Rates Track the RBA Cash Rate

Your variable interest rate is set by your lender as a margin above the Reserve Bank of Australia's cash rate. When the RBA raises or lowers the cash rate, variable mortgage rates move with it — usually within days for increases, sometimes weeks for decreases.

As of April 2026, the RBA cash rate is 4.10%. The average owner-occupier variable rate for principal & interest loans is 6.88% — a margin of 2.78% above the cash rate. Competitive discounted variable rates sit around 6.30% — a margin of 2.20%.

The key feature of a variable rate is that it floats. Every RBA decision is a potential change to your monthly repayment.

Fixed Rates Are Set by Swap Markets, Not the RBA

This is the part most borrowers miss. Your lender does not set fixed rates based on the current RBA cash rate. Fixed rates are priced off the wholesale interest rate swap market — where institutional traders price in where they expect the cash rate to be over the fixed period — plus the lender's margin.

Swap rates are forward-looking. They reflect the market's collective expectation of future RBA decisions. This means fixed rates can — and regularly do — move independently of the current cash rate and current variable rates.

Why This Matters Right Now

In April 2026, we have a rate inversion: 3-year owner-occupier fixed rates (6.00%) sit below the discounted variable rate (6.30%) and well below the average variable rate (6.88%).

This inversion tells you something specific: the swap market is pricing in multiple RBA rate cuts over the next 2–3 years. Traders expect the cash rate to fall from 4.10% to somewhere materially lower. When you fix at 6.00%, you are locking in a rate that the market believes will soon be above the prevailing variable rate — in other words, you may be fixing at the top.

This does not mean fixing is wrong. It means it is worth understanding what you are buying: certainty at a rate the market expects to become uncompetitive if its rate cut predictions are correct.

Comparing a 6.00% fixed rate to a 6.30% variable rate and choosing the lower number is the starting point, not the answer. The true cost comparison requires you to account for what happens after the fixed period ends — and that is where the real risk lives.

Monthly Repayments at Each Rate

On the benchmark $600,000 loan over 30 years (monthly principal & interest):

*Assumes the rate applies for the full 30 years, which it does not for a fixed-rate loan.

The Revert Rate Trap

When your 3-year fixed period ends, you do not automatically revert to the competitive discounted variable rate. You revert to the lender's standard variable rate (SVR) — which in April 2026 is 8.27%. That is 1.97 percentage points above the discounted variable and 2.27 points above your fixed rate.

Here is what that looks like in practice. After 3 years of fixed payments on a $600,000 loan at 6.00%, your remaining balance is approximately $576,500. Your repayment on the remaining 27 years:

That $857/month increase is the revert rate shock — and it hits automatically unless you take action before the fixed term expires.

The Cost of Inaction — Month by Month

Every month you sit on the SVR instead of switching to a competitive variable rate costs you approximately $950 in unnecessary interest (the difference in monthly interest charges on ~$576,500 between 8.27% and 6.30%).

Six months of inaction: ~$5,700 in extra interest paid. Twelve months: ~$11,400. This is money that goes directly to the lender's margin and buys you nothing.

What About the Comparison Rate?

For fixed-rate loans, the legally required comparison rate must factor in the revert to variable after the fixed period ends. This is why the comparison rate on a 3-year fixed product at 6.00% is always higher than 6.00% — it blends the fixed period with the higher revert rate plus fees.

The comparison rate is useful as a rough guide, but it has limitations: it uses a $150,000 benchmark loan (not $600,000), assumes no offset account or extra repayments, and uses a single average revert rate. For your actual cost comparison, use the worked numbers above or model your scenario with our calculator.

Fixing your rate is not inherently better or worse than variable. It is a tool with specific use cases. Here are the scenarios where it genuinely makes sense.

Budget Certainty When You Need It Most

If you are spending more than 30% of your gross household income on mortgage repayments, the difference between $3,597/month (fixed at 6.00%) and a potential $3,943/month (if variable rates rise to the average 6.88%) is not a rounding error — it is the difference between comfortable and stressed.

First home buyers, single-income households, and anyone with limited buffer benefit most from knowing the exact dollar amount leaving their account for the next 2–3 years. You cannot put a dollar value on the psychological benefit of certainty during the years when your budget has the least slack.

The Rate Inversion Signal

In a "normal" rate environment, fixed rates carry a premium over variable — you pay extra for certainty. Think of it as an insurance premium.

When fixed rates fall below variable — as they have in April 2026 — the insurance is free. You are getting certainty and a lower rate. This is rare, and it means the market is pricing in rate cuts that would eventually bring variable rates below where fixed rates are today.

The strategic question becomes: do you lock in the lower fixed rate now, or bet that variable rates will fall further than the market already expects?

The "Insurance Premium" Calculation

When fixed rates are above variable, the difference is the premium you pay for certainty. On a $600,000 loan, a 0.20% premium costs approximately $1,200/year — $3,600 over a 3-year fixed term. That is the price of insurance against rate rises.

When fixed rates are at or below variable (as now), the premium is zero or negative — you are being paid to take certainty. This changes the risk calculus entirely: you do not need to believe rates will rise to justify fixing. You only need to believe they will not fall dramatically faster than the swap market predicts.

Short-Term Certainty Through Life Events

Even if you would normally prefer variable, there are specific windows where rate certainty has outsized value: planning for parental leave, transitioning careers, approaching retirement, or any period where a surprise rate increase would be genuinely destabilising. A 1–2 year fixed term can bridge you through the uncertainty.

Variable rates sacrifice certainty for flexibility. Here is when that trade-off is worth it — and how to put a dollar value on the flexibility you are buying.

Full Offset Account Access

This is often the deciding factor. A variable-rate loan with a linked offset account lets you reduce your interest-bearing balance dollar-for-dollar with your savings — and most fixed-rate loans either do not offer an offset account at all, or cap it at $10,000–$50,000.

On the benchmark $600,000 loan at 6.30%, a $50,000 offset balance saves approximately $95,400 in interest over the life of the loan and pays it off roughly 4 years 2 months early. If you have $100,000 in offset, the savings grow to approximately $148,000.

Fixing at 6.00% saves you about $8,400 in total interest compared to 6.30% variable — but if you lose access to a $50,000 offset account to get that fixed rate, you lose $95,400 in potential savings. The offset wins by an order of magnitude.

For a detailed comparison of offset accounts and redraw facilities, see our offset vs redraw guide.

Unlimited Extra Repayments

Variable loans allow unlimited additional payments at any time. Every extra dollar goes straight to reducing your principal with no caps, no penalties, and no questions asked.

Fixed loans typically cap extra repayments at $10,000–$30,000 per year. If you exceed the cap, you face break cost fees. If you receive a $50,000 inheritance or work bonus and want to put it on the mortgage immediately, a variable loan lets you do it. A fixed loan may not.

Refinance Freedom

On a variable loan, you can refinance to another lender whenever a better deal appears. There is no penalty beyond the standard discharge fee (~$350).

On a fixed loan, refinancing during the fixed period triggers break costs — which can be substantial. If you fix for 3 years and a significantly better deal appears 12 months later, you may be trapped in a loan that no longer represents value.

Investment Property: The Tax Asymmetry

For investors, the interest on a mortgage is tax-deductible regardless of whether the rate is fixed or variable. But there are two less obvious considerations.

First, offset account access matters more for investors because redraw on an investment loan can contaminate your tax deductions. A variable loan with offset is the clean structure.

Second, a lower fixed rate means a smaller annual interest deduction. On a $600,000 investment loan, the difference between 6.30% variable ($37,800 in interest in year one) and 6.00% fixed ($36,000) is $1,800 less in deductions — roughly $700/year less tax benefit at the 37% marginal rate plus 2% Medicare levy. This does not make fixing wrong for investors, but it does partially offset the headline rate saving.

When You Expect Aggressive Rate Cuts

If you believe the RBA will cut rates more aggressively than the swap market is pricing in, variable lets you benefit from every cut in real time. With a fixed rate, you are locked in — and if variable rates fall below your fixed rate, you continue paying the higher amount or face break costs to exit.

Fixed-rate loans come with restrictions that variable loans do not. Some of these are minor inconveniences. Others can cost tens of thousands of dollars.

Limited or No Offset

Most fixed-rate home loans in Australia do not offer a full offset account. Some offer a partial offset — typically capped at $10,000 to $50,000. Banks restrict offset on fixed loans because a large offset balance effectively gives you a variable-rate benefit that undermines the bank's wholesale funding structure.

If your loan product does offer a partial offset on a fixed rate, check the cap carefully. A $20,000 partial offset saves approximately $1,260/year at 6.00%. That is better than nothing, but significantly less than the $3,150/year a full $50,000 offset saves on a variable loan at 6.30%.

For a detailed explanation of why banks limit offset on fixed loans, see our offset vs redraw guide.

Extra Repayment Caps

Fixed-rate loans typically cap additional repayments at $10,000 to $30,000 per year during the fixed period. This limit exists because extra repayments — like offset — undermine the lender's wholesale funding arrangements.

If you exceed the cap, the lender charges you break cost fees based on the same formula used for early termination.

Break Costs — How They Actually Work

Break costs are the single biggest financial risk of a fixed-rate loan, and most borrowers only discover how they work when they need to pay them.

The simplified formula:

Break cost ≈ (Your fixed rate − Current wholesale rate) × Remaining fixed term in years × Outstanding balance

The "current wholesale rate" is the swap rate for the remaining fixed period — not the RBA cash rate or the lender's advertised rate. This is important because swap rates can move significantly from where they were when you fixed.

Worked Example: A $17,400 Break Cost

You fixed $600,000 at 6.00% for 3 years. After 1 year, the wholesale 2-year swap rate has dropped to 4.50% (because the RBA has cut aggressively).

• Rate differential: 6.00% − 4.50% = 1.50%
• Remaining fixed term: 2 years
• Outstanding balance: approximately $580,000
• Estimated break cost: 1.50% × 2 × $580,000 = ~$17,400

This is not a fee the lender pulls from thin air. It is the bank's compensation for the mismatch between the wholesale rate they locked in to fund your loan and the rate they could now lend at. The larger the rate drop and the longer the remaining fixed term, the higher the break cost.

The One-Sided Asymmetry

If wholesale rates have risen since you fixed, your break cost is $0. The bank is happy — you are paying above the current market rate, which is profitable for them. But you do not receive the mirror benefit: if rates rise, you do not get a windfall payment from the bank.

This means the fixed rate contract is asymmetric: you bear the downside risk (break costs if rates fall) but do not capture the upside (no benefit if rates rise). The benefit you receive is certainty — which has genuine value — but the risk-reward is not symmetric.

If you have been reading this guide thinking "I want the certainty of fixed but I also need offset access," the split loan is designed for you.

How It Works

A split loan divides your mortgage into two separate loan accounts under one mortgage: one fixed, one variable. Each account has its own interest rate, repayment schedule, and features. The fixed portion gives you rate certainty. The variable portion gives you offset access, unlimited extra repayments, and refinance flexibility.

Most Australian lenders offer split loans as a standard option. You choose the ratio at the time of application (or when restructuring an existing loan), and you can typically adjust the ratio when the fixed period expires.

Common Split Ratios

There is no "correct" ratio. The right split depends on how much certainty you need, how much you have in offset savings, and whether you plan to make large extra repayments.

Worked Example: $600,000 Split 60/40

$360,000 fixed at 6.00% for 3 years, plus $240,000 variable at 6.30% — with $50,000 in an offset account linked to the variable portion.

The $50,000 offset reduces the effective variable balance from $240,000 to $190,000, saving approximately $3,150 per year in interest on the variable portion. This benefit is not available on the fixed portion.

Compare this to the all-fixed scenario at 6.00% ($3,597/month, no offset): the split costs $48/month more in repayments but saves $3,150/year in offset benefit. The offset benefit far exceeds the higher blended rate cost — provided you actually maintain the $50,000 balance.

Choosing Your Ratio

Two rules of thumb:

1. If your offset savings exceed $30,000, lean towards a higher variable portion. The offset benefit on the variable component compounds over time, and the more of your loan that is offset-eligible, the more value your savings deliver.

2. If budget certainty is your primary concern, lean towards a higher fixed portion. You want the largest share of your repayment to be predictable, with just enough variable to maintain offset access for your emergency fund.

The Investor Split Strategy

Investment property owners benefit from the split structure in two ways. The variable portion provides full offset access, avoiding the redraw contamination risk that threatens tax deductibility. The fixed portion provides rate certainty on the bulk of the loan.

Park your surplus cash in the offset against the variable portion. You reduce your interest cost daily, maintain full tax deductibility on the entire loan, and have the flexibility to withdraw funds without touching the loan itself.

Downsides

Split loans are not free of trade-offs. You will have two loan accounts to manage (though most lenders handle this seamlessly in their online banking). When the fixed portion expires, you face a decision on that component — refix, convert to variable, or refinance — while the variable portion continues unchanged. Some lenders charge a modest split fee ($100–$300) at setup.

The single most expensive mistake in fixed-rate lending is not the rate you choose — it is failing to act when the fixed period expires. If you do nothing, you automatically revert to the lender's standard variable rate (SVR), which in April 2026 is 8.27%.

The Revert Rate Shock in Dollars

After 3 years of fixed payments at 6.00% on a $600,000 loan, your remaining balance is approximately $576,500. Here is what happens to your repayment under different scenarios:

The difference between "switch to discounted variable" and "do nothing" is $748/month — or approximately $950/month in extra interest charges. Every month of inaction costs you nearly a thousand dollars.

Your Four Options at Expiry

1. Refix with your current lender. Lock in a new fixed rate for another 1–3 years. This is the simplest option if your lender is competitive and you want continued certainty.

2. Switch to the discounted variable with your current lender. Call the retention team and negotiate a competitive variable rate. You do not have to accept the SVR — but you do have to ask.

3. Refinance to a new lender. If your current lender will not match the market, refinance. Factor in discharge fees (~$350), any application or settlement fees with the new lender, and the time involved. For most borrowers, the rate saving far exceeds the switching costs.

4. Do nothing (never do this). You revert to the SVR. This is the worst possible outcome and the one that happens most often — because borrowers forget, procrastinate, or assume the lender will give them a good rate automatically. They will not.

The Timeline: Start 3–6 Months Before Expiry

Most lenders will let you lock in a new fixed rate 60–90 days before your current fixed term expires. Some allow up to 120 days. This means it is worth starting to compare rates and talking to brokers at least 3 months before your fixed period ends.

Set a calendar reminder for 6 months before expiry to begin research, and 90 days before to make your decision. This gives you time to negotiate with your current lender, get competing offers, and complete any refinance application if needed.

Negotiation Leverage

When you call your lender's retention team (not the general customer service line — ask specifically for the retention or loyalty team), you have more power than you think.

The cost of acquiring a new mortgage customer — through broker commissions, marketing, credit assessment, settlement — is typically $2,000–$5,000 for the lender. They would rather give you a 0.20–0.50% rate discount than lose you entirely. Come prepared with competitor offers, mention that you are considering refinancing, and be specific about the rate you want.

If the retention team cannot match the market, escalate. If they still cannot match, follow through on the refinance — the numbers usually justify the effort.

Rate Locks

If you are refinancing to a new lender as your fixed term expires, some lenders offer a rate lock — guaranteeing the quoted rate between application and settlement (typically 60–90 days). Rate locks usually cost $500–$750 or 0.10–0.15% of the loan amount.

A rate lock is worth considering if rates are rising or volatile. If rates are stable or falling, you may prefer to skip it and take the rate at settlement.

Instead of a vague "it depends on your circumstances," here is a structured framework with specific criteria.

Fix your rate if you...

• Are spending more than 30% of gross household income on mortgage repayments and need payment certainty
• Have a single household income with limited buffer for rate increases
• Have offset savings under $20,000 — the offset benefit you are giving up is small relative to the certainty you gain
• Want short-term certainty through a specific life event (parental leave, career change, contract ending)
• See fixed rates at or below variable — the insurance premium is free or negative, which is rare
• Are a first home buyer and the psychological certainty of a known payment helps you sleep at night

Stay on variable if you...

• Maintain $30,000 or more in an offset account — the interest saving from offset likely exceeds the rate saving from fixing
• Own an investment property where offset access protects tax deductibility and you need clean loan structure
• Want the ability to refinance or make large extra repayments without penalty (expecting a bonus, inheritance, or property sale)
• Believe rates will fall more aggressively than the swap market is currently pricing in
• Have a dual income household with comfortable buffer — you can absorb rate increases without financial stress

Split your loan if you...

• Want certainty on the majority of the loan but need offset access for at least $20,000–$30,000 in savings
• Want to hedge both directions — protected from rate rises on the fixed portion, benefiting from rate cuts on the variable
• Are an investor wanting to maximise both rate certainty and offset-based tax protection
• Have a moderate risk tolerance — comfortable with some rate exposure, but not comfortable with the full loan floating

Key Questions to Ask Yourself

1. What is my timeline? If you might sell, renovate, or refinance within the fixed period, break costs become a real risk.
2. What is my risk tolerance? Can your household absorb a 1–2 percentage point rate increase without financial stress? Use our rate stress test calculator to check.
3. How much offset do I have? If less than $20,000, the offset benefit you sacrifice by fixing is relatively small. If more than $50,000, it is very expensive to give up.
4. Am I an owner-occupier or investor? Investors need offset access for tax protection. The clean structure matters more than the rate saving.
5. Am I disciplined enough to act when the fixed term expires? If not, variable may be safer — there is no revert rate trap to fall into.

When to Reassess

Your rate structure is not permanent. Reassess at these trigger points:

• 3–6 months before your fixed term expires — start shopping for your next rate
• After a significant RBA move — a large rate cut may change the fixed vs variable calculus
• After a major life change — new job, new baby, partner returning to work, or approaching retirement all change your risk tolerance and cash flow
• When the rate inversion reverses — if fixed rates move back above variable, the "free insurance" window has closed

Not sure how your repayments would change under different rate scenarios? Try our mortgage calculator to model fixed vs variable outcomes, or use the rate stress test calculator to see how your repayments respond to 1–3 percentage point increases.