How the mortgage calculator works.
DTI rules, LVR, the KiwiSaver first-home withdrawal, and what this tool can and can't tell you.
QUESTIONS
Frequently asked questions
What is the DTI rule?
From mid-2024, the Reserve Bank introduced debt-to-income (DTI) restrictions: most owner-occupier loans are capped at six times gross household income; investor loans at seven times. The aim is to limit borrowers from taking on loans that become unserviceable if rates move.
Banks have policy exemptions and stress-test scenarios that go beyond the headline cap, so a real pre-approval can come in higher or lower than what this calculator shows.
How is LVR calculated?
Loan-to-Value Ratio (LVR) = the loan amount as a percentage of the property value. Loans above 80% LVR are “low-equity” and typically attract a low-equity premium (an additional interest margin) until the LVR drops below the threshold. We show your LVR tier and indicative low-equity premium based on standard NZ bank ranges — your bank's actual margin will vary.
How does the KiwiSaver first-home withdrawal work?
If you've been contributing to KiwiSaver for at least three years, are buying a first home you intend to live in, and meet income/price caps, you can withdraw most of your KiwiSaver balance for a deposit. We show whether you're eligible and the indicative amount you could withdraw.
You must leave $1,000 in your KiwiSaver account. The First Home Grant (a separate scheme) was discontinued in 2024.
What does this calculator NOT account for?
- Bank-specific stress tests (typically 8–9% test rate)
- Living expenses and existing debt servicing
- Lender's mortgage insurance (where applicable)
- Conveyancing, building inspection, and other settlement costs
- Council rates, body corporate fees, and ongoing maintenance
Should I rely on this for a property decision?
No. This is an educational calculator that shows you the rough shape of the maths under the regulatory framework. For an actual pre-approval — one a real estate agent will accept — you need a bank or mortgage broker. A licensed financial adviser can also help you weigh the decision against the rest of your finances.