Unpack Property
Costs - Tool 27

Auction max bid calculator

Stand at the auction. Open this on your phone. Enter cash + loan + state. The tool solves the absolute max you can bid - stamp duty, LMI and a buffer all included.

  • About 2 minutes
  • Data verified May 2026
  • Free, no sign-up

Your budget

Leave out money already spent, such as inspections.

Cash plus loan: $820,000.

You and the property

First home buyer
Property type
Buffer, deposit and settlement

Kept aside for over-runs and surprises after the hammer falls.

Usually 10%. The contract of sale sets it.

Settlement

Doesn't change the max bid. It sets how long you have to finalise the loan.

Your max bid

$752,734

The highest bid your cash and loan can cover once the deposit on the day, stamp duty, fees, any LMI and your 5% buffer are paid. Above this you are past your budget.

Comfortable bid (buffer kept aside)
$752,734
Hard mathematical ceiling
$782,863
Cash plus loan
$820,000

Max bid $752,734

No cooling-off at auction

Cooling-off does not apply at auction. Once the hammer falls and the contract is signed, you are committed.

Deposit on auction day: $75,273

That is 10% of $752,734, needed in cash on the day. Your $120,000 covers the deposit and the other upfront costs.

LMI applies at this bid

LMI of $14,258 applies because your LVR at this bid is 86.1%. Bidding less to get under 80% LVR can save the LMI cost.

Overbidding costs more than the bid

Bidding $37,637 above your max would add $8,632 of stamp duty (effective 22.9% on the extra). The real cost of overbidding is higher than the headline bid.

Where the money goes

Your bid plus every cost it brings, totalling $819,976.

Bid price
$752,734
Stamp duty
$11,051
Transfer + mortgage fees
$3,197
Conveyancing
$1,100
LMI
$14,258
Buffer
$37,637
Total
$819,976

Share with your partner

Copies your max bid, cash, loan, stamp duty, buffer and the deposit due on the day as plain text.

Stamp duty uses QLD rates for a home you will live in, with the first home buyer concession where it applies. Buying as an investor can mean more stamp duty in some states. Transfer, mortgage registration and conveyancing fees are typical QLD figures, and LMI is an indicative premium. Pest and building inspections are usually paid before the auction, so they are left out of cash on hand. Data as of May 2026.

Keep going

Tools people usually open around auction day.

Stamp Duty CalculatorGoes the other way: pick a price and see the duty. Useful when you have a target bid in mind.1 minTrue Cost CalculatorEvery upfront line item for a chosen price: conveyancing, inspections, application fees, moving and more.3 minBorrowing PowerNot sure of your pre-approval? Estimate the loan ceiling from income, expenses, deposit and rate buffer.2 minCooling-off CountdownSigning privately instead? Auction contracts have no cooling-off, but private treaty sales usually do.1 minBuilder Quote ComparisonBuying house and land instead of bidding? Compare builder quotes side by side.5 minLMI CalculatorYour LMI cost, upfront vs capitalised, and how FHG or Help to Buy can waive it.2 minSettlement Adjustment CalculatorAt settlement you reimburse the seller for prepaid council rates, water, and strata. Compute it line by line.2 minMoving CostsRemovalists, cleaning, connections, furniture, admin. Total your moving-day budget.2 min

Bidding at auction explained

An auction contract is unconditional from the moment the hammer falls. Australian state laws exempt auctions from the cooling-off period that protects buyers in private treaty sales, because the public bidding process is meant to set a binding price.
Data verified May 2026

For illustration only. This tool does not constitute personal financial advice. Grant amounts, caps, and eligibility rules may change. Federal scheme caps shown are for capital city/regional centres and may differ for other areas. Always verify with your state revenue office and Housing Australia, and consider seeking independent financial advice before making decisions.