About the Home Insurance Sum Insured Calculator
The 'sum insured' on a home insurance policy is the amount your insurer will pay to rebuild your home if it's a total loss. Setting it too low is a serious risk — this calculator gives a rough starting estimate based on your home's floor area, a per-square-metre rebuild rate, and typical extra allowances for demolition and professional fees.
How it works
- Base rebuild cost = floor area (sqm) × rebuild cost per sqm.
- Recommended sum insured = base rebuild cost × (1 + demolition & removal % + professional fees %).
- The demolition allowance covers clearing the site of a destroyed home before rebuilding; the professional fees allowance covers architects, engineers, and council/permit costs that a full rebuild typically needs on top of construction itself.
Assumptions and behaviour
- The default rebuild rate ($2,200/sqm) is a rough national midpoint — actual building costs vary a lot by location, home style, materials, and current construction market conditions.
- Assumes a standard single dwelling rebuild, not a heritage, architect-designed, or unusually finished home, which can cost significantly more per sqm.
- Does not account for detached structures (garages, pools, sheds) unless you've folded their area into the floor area figure yourself.
Limitations
- This is a rough estimate only, not a substitute for a proper valuation. Under-insurance is a real financial risk: if your sum insured is too low, you could be left paying the shortfall yourself after a total loss, and some policies apply a co-insurance penalty that reduces even a partial claim payout.
- Rebuild costs vary significantly by state, region, and current material/labour prices — this calculator can't reflect local conditions.
- Before setting your policy's sum insured, get an assessment from a registered valuer or licensed builder, or use your insurer's own rebuild cost calculator, which is typically tailored to your specific postcode and home type.
Privacy
The calculation runs entirely in your browser. Nothing is uploaded or stored.
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