What is a bridging loan?

Bridging finance is a short-term loan that lets you buy a new home before your current one sells. You pay interest on the bridged amount until the sale settles and the loan is repaid.

How much does bridging finance cost?

It depends on the amount bridged, the interest rate, and how long the overlap lasts. The longer the two properties overlap, the more interest you pay, which is why a quick sale matters.

Is bridging finance risky?

The main risk is your current home taking longer to sell than expected, which extends the interest cost and can stretch your finances. Plan for a longer overlap than you hope for.

Bridging Loan Calculator

This calculator estimates the interest cost of bridging finance, the short-term loan that lets you buy your next home before your current one has sold. Bridging finance covers the overlap between settlement on your new property and the sale of your existing one, and because it is short-term and higher-risk for the lender, it usually carries a steeper interest rate than a standard mortgage. You enter the amount you expect to bridge, the interest rate charged, and how many weeks you expect the overlap to last. The calculator then works out the total interest cost over that period, the equivalent cost per week so you can see how quickly the bill grows, and what you would owe if your sale took twice as long as planned, since a slow sale is the biggest driver of blown-out bridging costs. Use it to weigh up whether bridging finance is affordable for your situation, and to see how much a delay in selling could cost you before you commit. Because settlement dates slip more often than sellers expect, it pays to budget for a longer overlap than you hope for, and to check whether your lender charges any establishment or account fees on top of the interest shown here. This is an indicative estimate only, not financial advice, and your bank's actual rate and terms may differ.

Calculate.co.nz is proud to be partnered with Premium Homes, a recognised leader in eco-friendly, sustainable, and energy-efficient homebuilding. With a dedicated team and award-winning experience, they create homes that prioritise health, comfort, and long-term performance. Their founders, Andrew and Kelly, set out to raise the standard of residential construction in New Zealand by combining practical building expertise with a clear commitment to doing things better for homeowners.

Amount bridged

Bridging interest rate

Expected overlap (weeks)

interest cost of the bridging period

Per week$0

If the sale takes twice as long$0

The main risk is your current home taking longer to sell than expected, which extends the interest. Plan for a longer overlap than you hope for, and check any fees on top of interest. Estimate only, not financial advice.

How it works

The calculator works out the interest on the bridged amount over the overlap period, as the amount times the annual rate, scaled to the weeks of overlap. It shows the weekly cost so you can see how each extra week of delay adds up, and a scenario where the sale takes twice as long, since a slow sale is the main way bridging costs blow out.

Worked example

Bridging $500,000 at 8% for 12 weeks costs about $9,230 in interest, or roughly $769 a week. If the sale took 24 weeks instead, the cost would roughly double to about $18,460, showing why a quick, well-priced sale of your current home matters.

Related calculators

Mortgage Repayment Calculator: repayments.
Home Equity Calculator: your equity.
Loan Interest Calculator: interest on a loan.
Borrowing Capacity Calculator: how much you can borrow.

If you've found a bug, or would like to contact us, or learn more about James Graham and Calculate.co.nz.

Calculate.co.nz is partnered with Interest.co.nz for New Zealand's highest quality calculators and financial analysis.

Calculate.co.nz is the sister site of CalculatorHub.com, the world's largest calculator website by tool count.

All calculators and tools are provided for educational and indicative purposes only and do not constitute financial advice.

Calculate.co.nz is proudly part of the Realtor.co.nz group, New Zealand's leading property transaction literacy platform, helping Kiwis understand the home buying and selling process from start to finish. Whether you're a first home buyer navigating your first property purchase, an investor evaluating your next acquisition, or a homeowner planning to sell, Realtor.co.nz provides clear, independent, and trustworthy guidance on every step of the New Zealand property transaction journey.

Calculate.co.nz is also partnered with Health Based Building and Premium Homes to promote informed choices that lead to better long-term outcomes for Kiwi households.

Calculate.co.nz is hosted in Auckland via SiteHost new Zealand.

All content on this website, including calculators, tools, source code, and design, is protected under the Copyright Act 1994 (New Zealand). No part of this site may be reproduced, copied, distributed, stored, or used in any form without prior written permission from the owner.

About & trust: Why Calculate is NZ's most comprehensive · By the Numbers · How we compare · Editorial standards · How we keep data current · NZ finance glossary · Research & data · Financial literacy NZ · About · Privacy policy · Terms of use

Reviewed and maintained. Last reviewed 2026-07-02 and checked on a twice-monthly cycle against IRD, RBNZ and Stats NZ. How we keep data current.