GetPost Labs is a technology company. We work with property data: the data you supply (loans, rent, costs, documents) and the data we research (sales, rents, rates and rules), and we apply our experience in building data and software systems to lay it out clearly. The outcome is structured information to help you answer your own questions with data. It is not financial, tax, legal, credit or valuation advice, and it is not a recommendation to buy, hold or sell.
The property, address and owners in this example are fictional, and the figures are rounded 2026 assumptions. Real outcomes depend on your circumstances and the market, so check decisions with a licensed financial adviser, accountant or registered valuer.
The story
A couple bought a new four-bedroom house three years ago as an investment. It is let for $650 a week, but the rent does not cover the loan repayments and running costs, so they top it up by about $954 a month even after the tax refund.
They also have a home loan on the house they live in, at 6.2%. The question they asked: should we sell the investment now and put the money against our home loan, or hold it for ten years and sell then?
It depends on how fast the property grows. Below about 3.3% a year, selling now comes out ahead. At 5% a year, holding leaves them about $178,057 better off after ten years. The rest of this page shows how we got there.
The property
| Address | 21 Ironbark Lane, south-east QLD fictional |
| Property | 4 bed, 2 bath, 2 car house on 420 m², bought new three years ago as an investment |
| Owners | Two owners, 50/50, each on a 39% marginal rate (including Medicare levy) |
| Value today | $920,000 |
| Cost base (price plus duty and legals) | $725,000 |
| Investment loan | $577,321 left, 6.2% principal and interest, $3,675 a month |
| Rent | $650 a week, assumed to rise 3.0% a year |
| Their home loan | Also at 6.2%, with an offset account |
After the tax refund from negative gearing
After loan, selling costs and capital gains tax
A year, for holding to beat selling
If held
What holding costs each year
Rent does not cover the loan repayments and running costs, so the owners top it up. The loss is tax-deductible (negative gearing), including $10,000 a year of capital works deductions, which softens the cost.
| Year | Rent | Interest | Costs | Repayments | Tax refund | Top-up after tax |
|---|---|---|---|---|---|---|
| 1 | $33,800 | $35,554 | $9,400 | $44,098 | $8,250 | $11,448 |
| 2 | $34,814 | $35,009 | $9,682 | $44,098 | $7,752 | $11,214 |
| 3 | $35,858 | $34,429 | $9,972 | $44,098 | $7,232 | $10,980 |
| 4 | $36,934 | $33,812 | $10,272 | $44,098 | $6,688 | $10,747 |
| 5 | $38,042 | $33,156 | $10,580 | $44,098 | $6,121 | $10,515 |
| 6 | $39,183 | $32,458 | $10,897 | $44,098 | $5,527 | $10,284 |
| 7 | $40,359 | $31,716 | $11,224 | $44,098 | $4,906 | $10,056 |
| 8 | $41,570 | $30,926 | $11,561 | $44,098 | $4,258 | $9,831 |
| 9 | $42,817 | $30,085 | $11,908 | $44,098 | $3,579 | $9,610 |
| 10 | $44,101 | $29,191 | $12,265 | $44,098 | $2,868 | $9,393 |
Costs are rates, insurance, property management and repairs, rising 3.0% a year. Repayments include principal, which builds equity; the top-up is the cash the owners actually pay in.
Option A: sell now
| Sale price | $920,000 |
| Less selling costs (2.5%) | −$23,000 |
| Less loan paid out | −$577,321 |
| Capital gain: $897,000 less reduced cost base $695,000 | $202,000 |
| Capital gains tax: half the gain at 39.0% | −$39,390 |
| Cash in hand | $280,289 |
The cash goes into the home-loan offset, where it saves 6.2% interest, tax-free. The top-ups they no longer pay go there too. After ten years that adds up to $651,488.
The reduced cost base is the cost base less the capital works deductions already claimed. The 50% discount applies because the house was bought new before 12 May 2026; see the 2026 rules.
Option B: hold for ten years, then sell
What the owners end up with depends almost entirely on how fast the property grows.
| 3% growth | 5% growth | 7% growth | |
|---|---|---|---|
| Sale price in 10 years | $1,236,403 | $1,498,583 | $1,809,779 |
| Loan left | −$462,680 | −$462,680 | −$462,680 |
| Selling costs | −$30,910 | −$37,465 | −$45,244 |
| Capital gains tax | −$119,046 | −$168,893 | −$228,059 |
| Hold: cash after sale | $623,767 | $829,545 | $1,073,795 |
| Sell now: offset balance after 10 years | $651,488 | $651,488 | $651,488 |
| Holding is better (worse) by | ($27,721) | $178,057 | $422,307 |
Below about 3.3% a year, selling now and paying down the home loan comes out ahead. Above it, holding wins, and the gap widens quickly: at 5% the owners are about $178,057 better off holding.
Beyond the numbers
- Cash flow: holding needs about $954 a month from the owners in the first year
- Interest rates: a 1% fall in rates cuts the top-up by roughly $5,773 a year before tax
- Tax rules: the capital gains rules change from 1 July 2027; how they apply depends on the property
- Other plans: cash in the offset is available for other goals; equity in a property is not, unless you borrow against it
Method
Loan balances use monthly principal-and-interest repayments. Tax effect is the taxable rental result (rent less interest, costs and capital works deductions) at 39.0%. Both options keep spare cash in the offset at 6.2%, so they are compared on the same footing. Capital gains tax uses the 50% discount on the gain above the reduced cost base. Figures are rounded.
Everything on this page is for educational and informational purposes only. Costs, prices, interest rates, rules and government schemes change over time, and the figures shown are approximate examples that may already be out of date. Nothing here is financial, tax, legal, building or professional advice, a recommendation or a quote. Do your own research, get written quotes and seek advice from qualified professionals before making any decision.
PropertyMaths is being built by GetPost Labs Pty Ltd, a technology company. We are not financial, tax, legal or property advisers. The information here is our own research, shared to show what a product for property owners and investors could do.