Comp Valuation Calculator
Estimate a Fair Offer Price
Enter your target property and recent comparable sales — the calculator picks the two closest matches and adjusts for land size.
Your Valuation Anchor
Your valuation anchor
Enter the target property details and up to 5 recent comparable sales — we'll pick the two closest Original-condition matches and apply a land-size adjustment.
- Valuation anchor as a single dollar figure
- Line-by-line breakdown of chosen comparables
- Land-size adjustment of 1% per 25 sqm difference
Estimate a fair offer price from recent comparable sales. Enter your target property details and five recent sales — the calculator picks the two closest matches, adjusts for land size, and averages them into a valuation anchor.
How this calculator works
Gather five recent sales
Pull five recent sales from the same suburb — ideally settled within the last three to six months. Record each address, bed count, bath count, land size in sqm, condition, and sale price.
Filter to matching bed and bath
The calculator picks comps whose bed and bath counts exactly match your target. If none match, adjust the target figures or refresh your comparable sales list.
Apply the land-size adjustment
Each selected comp's sale price is adjusted by 1% per 25 sqm difference in land size — bigger blocks nudge the value up, smaller blocks nudge it down.
Average the two closest comps
The two best-matching adjusted prices are averaged to produce the valuation anchor. The result is rounded to the nearest $100 so you have a clean number to work with.
Use it as your anchor
Bring the anchor to your next inspection or negotiation as the evidence-backed starting figure — then adjust for features, condition, and demand to settle on a final offer.
Frequently asked questions
What is a comparable sale?
A comparable sale (or 'comp') is a recently sold property that shares key attributes with the one you're valuing — same suburb, similar bed and bath count, similar land size, and comparable condition. Agents, valuers, and banks all rely on recent comparable sales as the primary evidence of market value.
Why do I adjust for land size?
Two otherwise identical houses on different-sized blocks will sell for different amounts, because the land is doing most of the work for long-term capital growth. This calculator applies a simple adjustment of 1% per 25 sqm difference between the comparable sale and the target property — a practical rule of thumb that approximates typical suburban land value movements.
How many comps should I use?
Collect five recent sales so the calculator has enough data to find strong matches, but the valuation anchor itself only uses the two best matches — the ones with identical bed and bath counts and the closest condition to Original. Using fewer than two matches weakens the anchor.
Why does condition matter so much?
A renovated sale reflects the cost of the renovation on top of the underlying property value, so using renovated comps to value an Original-condition home systematically overstates the price. The calculator prefers Original-condition comps and falls back to renovated ones only when no Original sales are available.
Is the valuation anchor what I should offer?
No — the anchor is a reference point, not an offer. Use it as the starting figure you discuss with your buyer's agent or conveyancer, then adjust up or down for unique features (aspect, street position, recent works) and local demand conditions before making an offer.