Knowing how much you can borrow is the quiet first step in buying a place to settle. It turns a vague hope into a real budget, so you can search with confidence instead of falling for a home you cannot fund. Lenders look at far more than your salary, and the figure they land on can surprise people in both directions. This guide walks through what banks weigh up, why their cautious test rate matters, and the honest moves that lift your borrowing power so the family home feels reachable rather than uncertain.
Quick answer
Your borrowing limit comes down to three things working together: your income, your existing debts, and your deposit. A lender adds up what you reliably earn, subtracts your regular commitments and a generous estimate of living costs, then checks whether the leftover comfortably covers a mortgage repayment assessed at a higher test interest rate than the one you would actually pay. On top of that, loan-to-value ratio (LVR) rules cap how much you can borrow against the property, so your deposit size sets a ceiling too. As a rough guide many buyers are assessed on borrowing somewhere around four to six times their household income, but that is only a starting sketch; the real number is whatever a lender will sign off after running your full picture. The cleanest way to get a firm figure is pre-approval from a lender or a mortgage adviser, which is free to arrange and tells you exactly where you stand before you start looking.
The detail, in plain English
Lenders start with serviceability, which is simply whether you can service the loan month to month. They count stable income from salary, and often a discounted portion of overtime, bonuses, rental income or self-employed earnings, because they want figures they can count on. Against that they set your outgoings: other loan repayments, credit card limits (assessed even if you never use the full limit), car finance, buy-now-pay-later balances, and a standard allowance for everyday living that scales with your household size. Then comes the part that catches most people out, the test rate. Rather than checking your budget at the real mortgage rate, the lender stress-tests your repayments at a notably higher rate so they know you could cope if rates climbed. That is why your approved amount often feels conservative. Separately, LVR rules limit how much of the property value you can borrow, so a larger deposit both lifts your ceiling and can unlock sharper pricing. Each lender weights these inputs differently, which is exactly why two banks can offer two different numbers on the same income.
What it means for you
The practical takeaway is that your borrowing power is a moving figure you can influence, not a fixed verdict. Trimming or closing credit card limits and clearing short-term debts like car or personal loans can free up serviceability quickly, because lenders assess the limit, not just the balance. A bigger deposit, whether saved, gifted, or drawn from a KiwiSaver first-home withdrawal, lifts your LVR position and your ceiling at the same time. Showing steady, documented income matters more than a one-off bonus, so consistency helps. And because each lender runs the numbers their own way, the amount one bank declines, another may approve, which is where a mortgage adviser earns their keep by knowing which lender suits your situation. Going in with a clear, lender-confirmed budget also makes you a calmer, stronger buyer; you can move quickly on the right home and avoid the heartbreak of chasing something the finance was never going to reach.
Common questions
Does my deposit change how much I can borrow? Yes, in two ways: it sets a hard ceiling through LVR limits, and a stronger deposit can mean sharper interest rates and easier approval. Will my KiwiSaver count toward my deposit? Many members can make a first-home withdrawal to boost their deposit, subject to eligibility, which improves both your deposit and your borrowing position. Why is the approved amount lower than I expected? Almost always the test rate and your credit limits; lenders assess you at a higher rate and treat your full card limits as debt, even if unused. Should I get pre-approval before house hunting? Yes, it gives you a real budget, signals to sellers and agents that you are serious, and saves you chasing homes outside your range. How long does pre-approval last? It is usually valid for a set window and can be refreshed, so confirm the term with your lender or adviser and keep your finances steady in the meantime.
Your next step
The cleanest way to turn this from theory into a real number is to get pre-approval, and a good mortgage adviser can compare lenders so you are not relying on a single bank view. Maifang is free and independent; we are not tied to any lender, so the guidance is genuinely on your side. Tell us your suburb and whether you are buying your first home or upgrading, and we will match you with a licensed mortgage adviser who can confirm your borrowing power and structure a loan around your plans. There is no obligation and your details stay private. With a confirmed budget in hand, the search for a safe, lasting home in New Zealand gets a great deal calmer.
In plain English: Lenders work out what you can borrow from your income minus your debts and living costs, tested at a higher what-if interest rate, with your deposit setting the ceiling. Get free pre-approval to find your real number before you start looking.
General information, not personalised real-estate, legal or financial advice. Confirm your situation with a licensed adviser. Read the full disclaimer →