Two positions, compared year by year
The calculator runs both paths in parallel for as many years as you choose. On the buying side it amortises the loan month by month, grows the property at your assumed rate, and adds the costs renters never see — council rates, building insurance, strata and maintenance at 1% of value a year. Your net position is equity, minus about 2.5% selling costs, minus every dollar you have paid out.
On the renting side it does the thing most comparisons skip: it invests the entire upfront amount the buyer sank into the purchase — deposit, transfer duty, LMI and legals — plus any month where owning costs more than renting. Rent rises at your assumed rate each year. The renter’s net position is that portfolio minus the rent paid.
The break-even year is the first year the buyer’s net position overtakes the renter’s. Before it, renting is ahead; after it, buying is.
Worked example
An $850,000 purchase in NSW with a 20% deposit: $170,000 deposit, $32,437 transfer duty, no LMI, $2,200 legals — $204,637 upfront. The $680,000 loan at 6.20% over 30 years is $4,165 a month. Against $650-a-week rent growing 3.5% a year, with property growth at 4% and the renter earning 7% on the invested deposit, buying pulls ahead around year eight. Move the state to Victoria and duty jumps to $46,070, pushing break-even out by roughly a year on its own.