Whether debt recycling "works" at current interest rates isn't a matter of opinion — it's a break-even calculation. If your expected after-tax investment return exceeds your after-tax borrowing cost, the maths tilts in your favour. If it doesn't, the strategy destroys value. Everything else is noise.
The break-even concept
Debt recycling shifts a portion of your home loan from non-deductible to deductible. The interest on the investment split becomes a tax deduction, which lowers the real cost of carrying that debt. Your strategy is profitable when the investments funded by that debt earn more — after tax — than the debt costs you after the deduction.
In a formula:
Expected after-tax return > Loan rate × (1 − marginal tax rate)
The left side is uncertain (market returns vary year to year). The right side is known the moment you sign the loan. That asymmetry — certain cost versus uncertain gain — is the entire risk profile of the strategy, and understanding it starts with getting the right side right.
Your after-tax borrowing cost
Because the interest on your investment split is deductible under s 8-1 ITAA 1997, your real cost depends on your marginal tax rate (including the 2% Medicare Levy). For the 2025–26 financial year, the effective marginal rates most debt recyclers care about are 32%, 39% and 47%.
The table below shows the after-tax cost per dollar of interest across a range of loan rates:
| Loan rate | 32% marginal rate | 39% marginal rate | 47% marginal rate |
|---|---|---|---|
| 5.00% | 3.40% | 3.05% | 2.65% |
| 6.00% | 4.08% | 3.66% | 3.18% |
| 7.00% | 4.76% | 4.27% | 3.71% |
| 8.00% | 5.44% | 4.88% | 4.24% |
The formula is straightforward: rate × (1 − marginal rate). At a 6% loan rate and a 39% marginal rate, that's 6% × 0.61 = 3.66%. The higher your tax bracket, the cheaper the debt becomes after the deduction — which is why debt recycling tends to be more compelling for higher earners.
The return side of the equation
Long-run total returns on the Australian share market (ASX 200 including dividends) have historically averaged roughly 9–10% per annum over multi-decade periods. This figure includes capital growth plus dividends, and is often used as a starting point when modelling debt recycling outcomes.
Important: Historical returns are illustrative only and are not a reliable indicator of future performance. The actual return you experience will depend on the investments you choose, the period you hold them, and broader market conditions. Use these figures as a modelling input, not a promise.
If you assume a long-run return of 9% and your after-tax borrowing cost is 3.66% (the 6%-rate, 39%-bracket scenario above), the expected gap is around 5.3 percentage points. That gap is what builds your wealth over time: the investments earn more than the debt costs, and the surplus compounds year after year.
Franking credits on Australian equities can add further value. A fully franked dividend of $700 grosses up to $1,000, carrying a $300 franking credit that offsets your tax liability (and is refundable if your tax bill is already nil). This effectively boosts the after-tax yield on your portfolio, widening the gap further. Just keep in mind the 45-day holding rule if your franking credits exceed $5,000 in a year.
When higher rates erode the case
The table above makes the dynamic clear: as rates climb, your after-tax cost rises and the gap between cost and expected return shrinks. Consider two scenarios at a 39% marginal rate:
- 5% loan rate: after-tax cost = 3.05%. If you assume 9% returns, the gap is about 5.95 percentage points — a comfortable margin of safety.
- 8% loan rate: after-tax cost = 4.88%. The gap narrows to roughly 4.12 percentage points. Still positive on paper, but the buffer for a few bad years in the market is thinner.
The gap doesn't need to disappear entirely for the strategy to become unattractive. It just needs to shrink enough that the real-world risks — sequence risk, volatility, unexpected expenses forcing you to sell at a loss — outweigh the expected benefit. The smaller the margin of safety, the less room you have for the market to underperform without eroding your position.
Why a positive expected gap still isn't a free lunch
Even when the numbers look favourable on a spreadsheet, three risks make the outcome uncertain:
- Sequencing risk. If the market drops sharply in the early years of your strategy — before your portfolio has had time to grow — the loss hits a larger proportion of your invested capital. You're still paying interest on the full amount, but the investments have shrunk. The long-run average might be 9%, but the order in which those returns arrive matters enormously.
- Volatility drag. A portfolio that falls 20% then rises 25% is back to par — but one that fell 30% needs a 43% recovery. The compounding maths penalises large drawdowns more than simple averages suggest.
- Cost certainty versus return uncertainty. Your interest bill arrives every month like clockwork. Your investment returns do not. In any given year, the return side of the equation could be negative — while the cost side never is. You need to be financially and psychologically prepared to sustain the strategy through those years.
This is why debt recycling is generally considered more appropriate for people with a long time horizon (ten years or more), stable income and genuine surplus cash flow — not a strategy to stretch into when the budget is already tight.
Sensitivity: small changes swing the outcome
One of the most underappreciated aspects of the break-even analysis is how sensitive it is to small shifts in assumptions. Consider someone on a 39% marginal rate with a 6.5% loan:
- After-tax cost = 6.5% × 0.61 = 3.97%
- At an assumed 9% return: gap = 5.03 percentage points
- At an assumed 7% return: gap = 3.03 percentage points
- At an assumed 5% return: gap = just 1.03 percentage points
Dropping the assumed return from 9% to 7% nearly halves the expected margin. And 7% is well within the range of plausible outcomes over a 10-year window — it is not a pessimistic scenario.
The lesson: don't anchor on a single point estimate. Run the analysis across a range of return assumptions (say, 5% to 10%) and a range of possible interest rates. If the strategy only makes sense at the optimistic end, the margin of safety may not be there.
How to pressure-test it with the calculator
Our free calculator lets you model exactly this trade-off. Plug in your loan balance, rate and term; set your marginal tax rate; choose an assumed investment return; and compare the debt recycling path against simply paying off the mortgage. Then move the sliders:
- Raise the interest rate by 1–2 percentage points. Does the strategy still come out ahead?
- Lower the assumed return to 6% or 7%. How many years until the crossover?
- Try different marginal rates — particularly if a salary change or career break might shift your bracket during the strategy's life.
If debt recycling only looks attractive under a narrow set of assumptions, that's useful information. A strategy with a wide margin of safety across realistic scenarios is materially different from one that needs everything to go right.
Key takeaways
- Debt recycling's viability is a break-even question: does your expected after-tax return exceed your after-tax borrowing cost?
- The tax deduction substantially lowers the real cost of the investment loan — from 6% to as low as 3.18% at the top marginal rate.
- Historical ASX 200 total returns of roughly 9–10% p.a. suggest a positive gap in most scenarios, but past performance is not a guarantee of future results.
- Higher interest rates shrink the gap and reduce the margin of safety against bad market years.
- Test a range of assumptions, not a single point estimate — the strategy should hold up under conservative inputs, not just optimistic ones.
Run the break-even for your numbers
Model debt recycling against your actual loan rate, tax bracket and return assumptions — with 2025–26 rates, franking credits and CGT built in.
Open the free calculator →Common questions
Does debt recycling still work if rates go above 7%?
It can, but the margin of safety narrows significantly. At a 7% loan rate and a 39% marginal rate, your after-tax cost is 4.27%. If long-run returns average around 9%, there's still an expected gap — but less room for a few poor market years. The higher the rate, the more important it is to stress-test across conservative return assumptions.
Should I wait for rates to drop before starting?
Timing interest-rate cycles is difficult. What matters more than today's rate is whether the expected gap over your full investment horizon (ideally 10+ years) is positive under a range of scenarios. Delaying also means missing out on years of potential compounding. Focus on the structural question — is the strategy viable for you? — rather than trying to pick the perfect entry point.
Is the after-tax cost the same for a fixed-rate loan?
The formula is identical: rate × (1 − marginal rate). A fixed rate simply locks in the cost side for the fixed period, which can be an advantage because it removes rate uncertainty from the break-even equation during that term. The trade-off is that fixed splits often restrict extra repayments and redraws, which can complicate the recycling loop.