How much house can I afford calculator
Every bank has a calculator that answers this. They all answer a slightly different question: how much will we lend you. That's worth knowing, but it isn't the same as what you can comfortably pay, and the gap between the two is where people get into trouble.This one starts from the other end.
It starts with what you could actually pay
Instead of asking your income and applying a multiple, this calculator asks a question you can answer honestly: what's the most you could pay in rent each year and still be fine?
That's a number you already know from living your life. You know what rent felt comfortable, what felt tight, and what would have been too much. Working back from it gives you a purchase price grounded in your actual spending rather than a formula.
If you already own and you're looking to upsize, enter the most you could spend on a mortgage each year in cell C11 instead.
You'll also need some estimates for the running costs of the new place and a few mortgage assumptions. From there you get the price you could likely afford, what the annual cost of owning it would be, and what share of your income that represents.
Three things cap what you can buy, and the smallest one wins
The price this calculator gives you is one of three limits. Your actual ceiling is whichever is lowest.
What you can comfortably pay. What this calculator works out.
What the bank will lend you. Since July 2024, banks work within Reserve Bank debt-to-income limits. 6 times gross income for owner-occupiers, 7 for investors. For a lot of buyers that's now the binding constraint, not the deposit or the repayments.
Your deposit. Usually 20% to avoid a low-equity premium, though there are routes below that.
People tend to find out about the second and third ones from the bank, late, after they've been looking at houses in a price range that was never available to them. Worth checking all three before you start.
Don't buy at the maximum
The number this gives you is a ceiling, not a target.
You want room for things not going to plan. A rate rise at the wrong moment, a period out of work, a roof that needs doing. Money left over after the deposit helps, so does an emergency fund and proper insurance, and so does job security.
Every situation is different. The better your planning and the more you've done to reduce your risks, the closer to your limit you can sit comfortably. But the limit itself isn't where anyone should be aiming.
Historical housing affordability in New Zealand
How does today compare with the past in your region? The NZ housing affordability calculator compares median house prices with household incomes in 10 regions since 2005. It covers house price to income, repayments and deposits, and works out the income you’d need to buy the median house.
Not sure whether buying stacks up at all?
Working out what you could pay is a different question from whether you should. If you'd like to talk through whether buying fits your wider plan and what you'd be committing to afterwards, get in touch for a free 30 minute chat. Independent, and I don't sell mortgages.
Related reading
Is housing affordable in 2026? - where affordability sits right now, and why more people aren't buying
Historical housing affordability data - the thinking behind the dataset above, and what the trends show
The not so hidden costs of home ownership - why the true cost of owning is higher than most people count
Related calculators
Saving for a house deposit - how long it'll take at your current savings rate, or what you need to put aside each month to hit a date
Debt to income calculator - the Reserve Bank limit on what a bank can lend you, which is often the real cap
Rent or buy a house - the full cost of both over the years you'd actually stay
Mortgage calculators - repayments, extra payments, rate changes and bank offers
Shared home ownership (You Own) - what a shared ownership scheme costs over time