Rent vs buy calculator
See whether renting and investing the difference, or buying, leaves you better off after a given number of years.
Wealth over time
Buying equity vs renting-and-investing wealth, year by year — watch where the lines cross.
What this means for you
See how sensitive this result is to your time horizon — a few extra years can change which option wins.
Compare time horizons
This result is sensitive to how long you hold — see how the verdict shifts over a shorter or longer horizon.
| Scenario | Verdict | Buy equity | Rent wealth | Difference |
|---|---|---|---|---|
| Current (10 years) | — | $0 | $0 | $0 |
| 5 years less | — | $0 | $0 | $0 |
| 5 years more | — | $0 | $0 | $0 |
Buying tends to strengthen the longer you hold, since equity keeps building while transaction costs (not modelled here) get spread over more years.
Assumptions & sources
Property growth and investment return are user-adjustable estimates — there is no single official forecast for either, so treat the defaults as a reasonable starting point, not a prediction.
1 July 2026
17 July 2026
Buying: home value compounds at your growth rate; equity is that value minus the remaining mortgage balance. Renting: your deposit plus any monthly surplus (if renting costs less than owning) compounds at your investment return rate.
Mortgage principal and interest, an estimated 1.5%/year for rates, insurance and maintenance, and rent.
Buying and selling transaction costs (legal fees, agent commission), tax on investment returns, and any rent increases or renovation costs over time.
How this comparison works
Buying builds wealth through home equity — the gap between your home's value and what you still owe on the mortgage. Renting builds wealth by investing what you're not spending on a deposit and, if renting is cheaper than owning month-to-month, investing that monthly saving too. This calculator tracks both paths over the same number of years and compares the net result.
The result is sensitive to your assumptions, especially property growth and investment returns — small changes to either can flip the outcome, so it's worth testing a few scenarios rather than trusting a single result.
Example: A $600,000 Christchurch townhouse vs renting
Aroha is deciding between buying a $600,000 townhouse in Christchurch with a $100,000 deposit, or renting an equivalent home for $550 a week and investing the difference.
At 5.59% over 10 years, buying would leave her with approximately $475,000 in home equity (after her remaining mortgage balance), assuming 4% annual property growth.
If she rented instead and invested her $100,000 deposit plus the monthly difference between renting and owning at a 5% return, she'd have approximately $356,000 after 10 years.
In this scenario, buying comes out around $118,000 ahead over the 10-year window — though that gap narrows or reverses at lower property growth rates, higher investment returns, or a shorter time horizon, which is exactly why it's worth running your own numbers above rather than relying on a rule of thumb.
Frequently asked questions
It depends on your deposit size, local rent-to-price ratios, how long you'll stay, and what you'd do with your money otherwise. Buying tends to win over longer horizons with reasonable property growth. Renting and investing can win when rents are low relative to buying costs, or over shorter timeframes.
Beyond the mortgage payment, owning includes rates, insurance and maintenance — commonly around 1-1.5% of the property's value a year. Renting has no equivalent costs but builds no equity. This calculator tracks net wealth over time to account for both.
