Australian property calculators have a credibility problem. Most of the free tools online are built off generic mortgage formulas, ignore state-specific tax rules, and exist primarily to harvest leads for a panel of lenders. The 18 calculators on this hub are built differently. Every formula has been tested against worked examples published by the ATO, state revenue offices, APRA, and the Reserve Bank of Australia. Every result links back to its source so you can verify the numbers yourself. Nothing is gated, nothing is monetised through lead capture, and nothing nudges you toward a specific lender.
The hub covers the full lifecycle of an Australian property transaction. On the borrowing side, the mortgage repayment calculator handles principal-and-interest and interest-only schedules with offset and extra-repayment modelling, and the borrowing power calculator applies the 3% APRA serviceability buffer using HEM-style living expense floors rather than the optimistic numbers a broker portal might show. On the upfront cost side, the stamp duty calculator implements the actual bracket schedules for all eight states and territories — including foreign purchaser surcharges, off-the-plan concessions, and first home buyer thresholds that differ by jurisdiction — and the LMI calculator uses Genworth and QBE premium tables rather than a flat percentage estimate.
Holding-cost tools are where most calculator sites fall short. The land tax calculator is built per-state because the thresholds, rates, and trust surcharges in NSW, Victoria, Queensland, WA, SA, Tasmania, and the ACT have nothing in common with each other. Victoria's vacant residential land tax, Queensland's absentee owner surcharge, and the ACT's marginal rates on unimproved value all behave differently and the calculator reflects that.
What separates this hub from finder.com.au, Canstar, or a major bank's calculator suite is editorial independence. There is no commercial relationship with any lender, mortgage broker, or buyer's agent. The methodology is published, the assumptions are exposed in the UI, and the formulas are auditable. If a state revenue office updates a duty schedule or APRA changes the serviceability buffer, the calculator is updated within the week and the change is logged.
Use the calculators below either as a starting point for a property decision or as a sanity check against numbers a broker, agent, or accountant has given you. Each tool links to the underlying explainer article and the relevant primary source so you can dig deeper when the answer matters.