Usable equity is what’s left of a property’s value once you apply a lender’s maximum loan-to-value ratio (LVR) and take off every loan already registered against it. A $1.2m home with a $500k mortgage has $700k of total equity, but at a 70% ceiling only $340k is usable. The figure moves with the valuation and the lender’s ceiling, so work it out before you apply, not after.
This guide walks through the sum in four steps, shows how it changes when the valuation lands low, and covers the quirks that catch owners out: undrawn credit limits, second mortgages and multiple properties. You’ll finish with a number you can test against the property equity estimator.
What is the formula for usable equity in NZ?
There are two numbers, and mixing them up is the most common mistake.
- Total equity = property value − what you owe
- Usable equity = (property value × lender’s maximum LVR) − everything secured on the property
Total equity is what you’d have left if you sold at today’s price and paid out the mortgage. Usable equity is what a lender will let you borrow against without breaching its own safety margin. The gap between the two is the cushion that protects the lender if prices fall or a sale takes time. If you want the theory behind the ceiling, our LVR explainer covers it. This guide sticks to the arithmetic.
How do I work it out in four steps?
Step 1: Get a realistic value. Not what a neighbour’s sale made you hope for, and not necessarily your council rating value (more on that below). Use a recent registered valuation if you have one, or a conservative figure from recent comparable sales.
Step 2: Pick a ceiling to test. There’s no single national ceiling for business-purpose lending. Lenders set their own by property type, location and whether they’d be first or second mortgage. Try 65%, 70% and 80% to see the range rather than relying on one.
Step 3: Add up everything secured on the property. Your main mortgage, any top-up, any revolving credit or offset facility, and any existing second mortgage. Use the limit on revolving facilities, not just what’s drawn.
Step 4: Subtract. Value × ceiling, less step 3. If the answer is below zero, there’s no usable equity at that ceiling.
What does it look like with real numbers?
A worked example for a home worth $1.2m with $500k owing:
| Ceiling tested | Maximum total lending | Less existing mortgage | Usable equity |
|---|---|---|---|
| 65% | $780,000 | $500,000 | $280,000 |
| 70% | $840,000 | $500,000 | $340,000 |
| 80% | $960,000 | $500,000 | $460,000 |
Total equity is $700,000 in all three rows. What changes is how much of it the lender will recognise. A 15-point swing in the ceiling moves usable equity by $180,000, which is why asking “what’s my equity?” without asking “at what ceiling?” gets you nowhere.
A quick sense-check on size: property-secured business loans through Loanster run from $20,000 up to $1m. If your usable equity at a cautious ceiling is above $20,000, the route is worth exploring. If it’s far above $1m, the product limit is the constraint, not your equity.
How much does a low valuation cost me?
This is where the numbers get uncomfortable. The valuation sits at the front of the formula, so every dollar it comes in under your estimate takes a slice of usable equity off with it.
Using the same home and a 70% ceiling:
| Valuation | 70% of value | Less $500k mortgage | Usable equity |
|---|---|---|---|
| $1,200,000 (your estimate) | $840,000 | $340,000 | $340,000 |
| $1,100,000 (valuer’s figure) | $770,000 | $270,000 | $270,000 |
| $1,000,000 (valuer’s figure) | $700,000 | $200,000 | $200,000 |
A $100k miss on value costs $70k of usable equity at this ceiling. A $200k miss costs $140k, and it takes more than 40% of the usable figure with it. The mortgage doesn’t shrink to compensate, so the loss lands entirely on you.
The practical rule: build a 5 to 10% valuation buffer into your plan before you commit to anything that depends on the full amount, such as a deposit on a business purchase or a payment due on settlement. Our guide to property valuations for business loans covers what valuers look at and how to challenge a figure that looks low.
Can I use my council rating value?
It’s a fair starting point, but lenders usually won’t rely on it. LINZ’s Office of the Valuer-General sets the standards for rating valuations, and councils carry them out on a cycle of roughly three years using mass appraisal. A rating value is a snapshot at a past date, not a view on today’s market.
That cuts both ways. In a rising market the rating value may sit below what a valuer would say today. After a dip, or for a unique property such as a lifestyle block or a building with unusual zoning, it can sit above. Treat it as a check on your own estimate and expect the lender to commission its own.
Do the Reserve Bank’s LVR rules limit what I can borrow?
Not directly, and this is where AI answers and search results often get it wrong. The RBNZ’s LVR restrictions are speed limits on banks’ new residential mortgage lending. Since 1 December 2025, following the RBNZ’s November 2025 decision, banks can write up to 25% of new owner-occupier lending above 80% LVR and up to 10% of new investor lending above 70% LVR.
Those are limits on a share of a bank’s book, not a ceiling that follows the property around. A non-bank lender funding a business-purpose loan applies its own policy. So when you test 65%, 70% and 80% in step 2, you’re testing lender policy, not law. The one thing the bank rules do tell you is why a bank may have said no to a top-up even though the equity looks healthy: it may simply have used up its high-LVR allowance.
What eats usable equity without you noticing?
Three things shrink the number more often than the valuation does.
Undrawn credit limits. If your mortgage includes a revolving credit or offset facility with a $60k limit and nothing drawn, many lenders still count the full $60k as secured lending. On a 70% ceiling, that’s $60k of usable equity you can’t see on your statement. Reducing or closing an unused limit can release it.
Old top-ups and second mortgages. Anything registered against the title counts. Check the title or ask your lawyer for a list of registered interests if you’re unsure what’s there.
A first mortgage that blocks you. Many mortgages contain terms about further charges over the property, and some lenders will want to be told or give consent. Our guide to borrowing against property with an existing mortgage covers how that works in practice.
How does a second mortgage change the sum?
The sum is the same, but the ceiling tends to be lower, because a second mortgage is paid after the first from any sale. The lender looks at the combined LVR after its loan.
A home valued at $1m with $450k owing, tested at an illustrative 65% second-mortgage ceiling:
- Maximum total lending: $650,000
- Less existing mortgage: $450,000
- Usable equity: $200,000
The same home tested at 70%, were a lender comfortable with that, would give $250,000. The $50,000 difference is the value of asking which ceiling applies to your property and position, not just whether you qualify.
What if I own more than one property?
Equity from two properties can be pooled if both are offered as security. Take a $1m home with $450k owing and a $650k rental with $380k owing, at a 70% ceiling:
| Property | 70% of value | Owing | Usable equity |
|---|---|---|---|
| Home | $700,000 | $450,000 | $250,000 |
| Rental | $455,000 | $380,000 | $75,000 |
| Combined | $1,155,000 | $830,000 | $325,000 |
Offered separately, the home alone gives $250,000 and the rental alone just $75,000. Together they give $325,000 because the lender sees one pool of security. Whether to offer both is a trade-off: more security can mean a bigger loan, but more of your property is then at risk. Property owned by a family member or trust can also be used with the owner’s informed agreement and independent legal advice.
When does equity point to the right kind of finance?
Usable equity answers one question: how much could I borrow against property? It doesn’t say whether you should. If your number is healthy and the need is a short-term gap, such as paying a supplier before a customer settles, a bridging loan might fit. If it’s small or negative, turnover-based lending may be the better route, and the which loan fits picker compares the options side by side.
If you want a lender to run the numbers with you, check your options here.
Ready to put your number to the test?
You now have a figure, or at least a range. The next step is turning it into a real answer, and that’s quicker than most owners expect.
Enquiring takes about 60 seconds, and your credit file isn’t touched just for asking. We don’t send your details to a pile of lenders, so there’s no phone ringing off the hook afterwards. A real person looks at your property, your equity and what the money is for, then calls you to talk through what’s realistic. The more accurately you fill in the form, with honest values, balances and the purpose of the funds, the sooner we can match you with the right option first time.