The Regime Investor· ·9 min read
Home insurance excess calculator: when does a higher excess pay off?
Compare two like-for-like Australian home-insurance quotes, calculate the break-even period for a higher excess, and test zero, one or two claims without guessing the odds.
Data checked: 2026-09-08
A higher home-insurance excess can lower the annual premium. That trade can look attractive at renewal: save money every year and pay more only if a claim occurs. The problem is that the saving arrives in small annual amounts, while the extra excess can be due when the household is already dealing with damage or loss.
The useful comparison is not “high excess or low excess?” in the abstract. It is a comparison between two real quotes for the same cover. Once those quotes are genuinely like for like, three numbers make the trade visible: the annual premium saving, the extra excess per applicable claim, and the accessible cash left after paying the higher excess.
This article gives you the arithmetic and a reusable calculator. It does not predict whether you will claim, choose a policy for you, or replace the Product Disclosure Statement (PDS) and certificate of insurance.
Make the two quotes like for like first
Moneysmart advises comparing the premium for the same type and level of cover. That condition matters more than the formula. A cheaper quote is not a saving if it also removes an event you need, lowers the sum insured, adds an exclusion or changes a benefit cap.
The safest method is to generate two quotes from the same insurer in the same session and change only the voluntary excess. Check that both quotes use the same:
insured address and policy period
building, contents or combined cover
sum insured and replacement-cover setting
covered events and optional benefits
exclusions, limits and special conditions
payment frequency and total annual price
Also open the Key Fact Sheet and PDS. The Key Fact Sheet helps compare policy features in a standard format; the PDS contains the detailed exclusions, caps, limits and conditions. Your certificate of insurance then records the settings and amounts that apply to your policy.
If anything other than the voluntary excess changed, stop. The calculator cannot separate the value of different cover from the price effect of a different excess.
Calculate the annual saving and extra claim cost
For two comparable quotes, label the lower-excess option Quote A and the higher-excess option Quote B.
Annual premium saving = Quote A annual premium − Quote B annual premium
Extra excess per applicable claim = Quote B excess − Quote A excess
Claim-free break-even years = extra excess per claim ÷ annual premium saving
The division works only when Quote B has a lower annual premium and a higher excess. If the annual premium saving is zero or negative, the higher excess does not earn back its extra claim-time cost in this simple comparison.
Break-even years answer one narrow question: how long would the annual saving take to equal the extra excess if no applicable claim occurs before then? It is not the expected time until a claim and it does not say which option is suitable.
Worked example: a five-year break-even
Suppose Quote A costs A$1,800 a year with an excess of A$500. Quote B keeps the cover unchanged, costs A$1,400 a year and has an excess of A$2,500.
Annual premium saving: A$1,800 − A$1,400 = A$400
Extra excess per applicable claim: A$2,500 − A$500 = A$2,000
Claim-free break-even: A$2,000 ÷ A$400 = 5 years
Over a five-year comparison period, the scenarios are:
Try your numbers
Compare your premium and excess
Change like-for-like quotes, the comparison period and accessible cash to compare the zero-, one- and two-claim scenarios.
Loading calculator. If it does not appear, you can still read the calculation explained in the article.
Show the original five-year example
| Applicable claims | Net saving over five years |
|---|---|
| Zero | A$2,000 |
| One | A$0 |
| Two | −A$2,000 |
Those are deterministic scenarios. They show what follows from the inputs; they do not assign a probability to zero, one or two claims.
The same formula works for a different horizon:
Scenario net saving = years × annual premium saving − claim count × extra excess per claim
Use the actual annual total from each quote. Do not multiply a monthly instalment by twelve unless you have checked that this captures every instalment fee and gives the same annual basis as the other quote.
Test claim-time cash separately
The break-even can favour the higher excess while the household cash position rejects it.
Add one more input: accessible emergency cash before a claim. Then calculate:
Cash remaining after higher excess = accessible emergency cash − higher excess
In the worked example, assume accessible emergency cash is A$5,500. Paying the A$2,500 higher excess leaves A$3,000. Whether that is enough depends on the household’s other essential costs and on how the insurer settles the claim. The calculator shows the number; it does not declare it adequate.
This is why an excess is not merely an investment-style return choice. The premium saving is gradual. The claim contribution can arrive at a stressful time, and Moneysmart notes that the policy specifies the excess before the insurer pays the balance; with a cash settlement, the excess may be deducted from the payment.
For a home buyer, the cash reserve also has jobs beyond insurance. Our guide to three separate first-home-buyer buffers explains why passing a lender’s serviceability test does not replace accessible cash for repairs, insurance excesses or an income interruption.
The excess you choose may not be the only excess
The voluntary excess displayed in a quote is not always the total contribution for every event. The PDS and certificate determine what applies.
AAMI provides a useful product-specific example. Its current explanation says the certificate shows the applicable excess amounts and types, and that an additional or unoccupied excess may apply in some circumstances. For a combined building-and-contents claim arising from one incident, its own rules determine which excess applies, plus any other applicable excesses.
That is not a rule to copy across every insurer. It is a reason to read your own documents. Before entering two excess amounts, check:
whether the selected excess applies to the event you are considering
whether an additional, event-specific or occupancy-related excess could also apply
whether building and contents claims attract one excess or more than one
whether the excess is paid directly or deducted from a settlement
whether any cover has an excess-free condition
The simple calculator deliberately excludes these variations. If another excess could change the decision materially, calculate that event separately using the exact policy terms or ask the insurer to explain the claim example in writing.
Do not fund the premium saving by weakening the cover
The excess decision and the sum-insured decision solve different problems. A higher excess changes how much cash you contribute to an applicable claim. The sum insured limits how much protection may be available to rebuild the home or replace contents.
Moneysmart warns that the cheapest policy may not provide the cover you need and recommends checking rebuilding costs, exclusions, caps and special conditions. The Insurance Council’s building and contents calculators can help estimate replacement costs, but the Council describes their results as approximate guides, not advice or a product recommendation. Unusual properties or hazard-zone rebuilding requirements may need a qualified professional estimate.
Do not lower the sum insured, remove a needed event or accept a materially different limit merely to create a larger apparent premium saving. First choose the protection you are comparing; then test the excess within that like-for-like cover.
This distinction matters for property risk as well as household budgeting. Our analysis of insurance as a local housing-stress channel explains how rising premiums, higher excesses or narrower cover can affect particular households and postcodes without proving a national financial crisis.
What the calculator shows
Enter six values in the calculator. The starting values match the worked example:
annual premium with the lower excess: A$1,800
annual premium with the higher excess: A$1,400
lower voluntary excess: A$500
higher voluntary excess: A$2,500
comparison period: 5 years
accessible emergency cash: A$5,500
The results show the annual premium saving, extra excess, claim-free break-even years, zero/one/two-claim outcomes and cash remaining after the higher excess. If the quotes are reversed, the annual saving is not positive, or the higher excess is not actually higher, the break-even result is unavailable. Check the inputs and the explanation beside the result.
Compare the labelled zero-, one- and two-claim scenarios separately. If the interactive calculator is unavailable, use the worked example above: it includes the formulas and all three scenario outcomes.
The calculator runs in your browser. It does not ask for an address, name, policy number or insurer login, send your inputs over the network, or save them after you close the page.
A renewal workflow that avoids false precision
Use the calculator in this order:
Obtain two current quotes with the same insurer and cover settings.
Read the Key Fact Sheet, PDS and quote details; confirm that only the voluntary excess changed.
Enter the annual total premiums and excesses.
Choose a comparison period you can understand rather than a horizon that flatters one option.
Read the zero, one and two claim outcomes as scenarios, not forecasts.
Check the accessible cash remaining after the higher excess.
Review any additional excesses or conditions outside the simple model.
Re-run the comparison at renewal because premiums, excess options and household cash can change.
The result can guide a better question. For example: “The higher excess saves A$400 a year and needs five claim-free years to equal the extra A$2,000. Would I still keep enough accessible cash if I had to pay A$2,500 next month?” That is more useful than treating the cheapest premium as the automatic winner.
What would change the decision
The higher-excess option becomes more attractive when the annual saving rises, the incremental excess falls, the comparison period lengthens and the household can comfortably meet the larger claim contribution. It becomes less attractive when the premium gap narrows, other applicable excesses increase the claim-time cost, accessible cash falls or the cover is no longer like for like.
A claim history may prompt questions, but this calculator does not turn it into a probability estimate. A household that wants an expected-value model would need a defensible estimate of claim frequency and which claims attract which excesses. Personal experience alone is usually too small a sample to support precise odds, and insurer pricing is not a personal forecast of next year’s claim.
The break-even number is therefore a decision aid, not a verdict. It makes the trade explicit and keeps the cash constraint visible. The final policy choice still depends on the cover required, the exact policy documents and the household’s capacity to absorb the excess.
General information only. This article and calculator do not take account of your objectives, financial situation or needs and do not recommend an insurer or policy. The operator or author may directly or indirectly use or hold insurance or financial products discussed here. The article was not commissioned or sponsored by an insurer, broker or comparison service and contains no affiliate or referral links. Display advertising does not determine editorial judgement. Read the current PDS, Key Fact Sheet, certificate and quote, ask the insurer about uncertain terms, and consider qualified advice where appropriate.
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