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NZ home energy planning
Heat Pump Calculator NZHeat pump size calculator NZ, cost and running-cost guide
Estimate heat pump size in kW, installation cost and yearly running cost for your New Zealand home. Adjust the assumptions so the result reflects your region, insulation and how you actually heat.
New Zealand regionsIndicative rangesNo sign-up
Heat pump estimate
Start with your space.
Choose a room or whole home, then adjust the details. Have your power bill handy for the electricity rate.
Your planning range
Heat pump estimate
Indicative NZD range, before any grant.
Based on your usage and electricity rate.
Estimated design load—
Estimated heat delivered—
Grant-adjusted budget—
How we reached this range
Heat pump calculator NZ guide
Heat pump cost calculator NZ: Compare size, cost and running cost before you request quotes.
This tool is designed for one of the more common New Zealand decisions: choosing a heat pump for one room, comparing a multi-room system with ducted heating, or checking whether a quote looks plausible for your home.
Enter your region, floor area, ceiling height, building age, insulation, glazing and exposure. The result combines an indicative heat-loss proxy with a dated NZ installation pricebook and your electricity rate. It covers Auckland, Hamilton, Wellington, Christchurch, Dunedin and other NZ locations.
Use this heat pump sizing guide when you're wondering, “What size heat pump do I need in NZ?” or comparing heat pump size options. It explains the basics of determining heat pump size and how many heat pumps you may need.
Feel free to use the result as a quote brief. Ask an installer to confirm capacity at local design temperatures, outdoor-unit placement, pipe runs, electrical work, drainage, zoning, warranty and any changes needed to meet current requirements.
Common NZ questions
Heat pump calculator FAQ
How accurate is this heat pump size calculator?
This is an indicative planning range using area, ceiling height, insulation, glazing, exposure and region. A qualified NZ installer should complete the final room-by-room heat-loss assessment.
How much does a heat pump cost to install in NZ?
Published NZ guides commonly place a single high-wall split around $2,000–$6,500, multi-split systems around $5,000–$10,000 and ducted systems around $10,000–$35,000, depending on scope and access.
What size heat pump do I need in NZ?
As a rough guide, a well-insulated 30m² room often falls near 4–5kW and a 60m² open-plan area near 7–9kW. Windows, insulation, ceiling height and local climate can change the result.
How many heat pumps do I need?
One unit can suit a well-connected open-plan zone. Separate rooms, floors or closed-off layouts may need multiple indoor heads or a ducted design; use room-by-room detail and ask an installer to confirm.
How does determining heat pump size work?
Heat pump sizing considers room volume, insulation, glazing, exposure, local climate and the target temperature. The calculator provides a planning estimate, while an installer checks the equipment’s output at cold outdoor temperatures.
Can I use a Warmer Kiwi Homes grant estimate here?
Yes, as a scenario only. Check current EECA eligibility, caps, funded system types and provider availability before relying on any grant-adjusted figure.
Designed for real NZ decisions
A number is useful when its assumptions are visible.
Capacity
We use volume, insulation, glazing and regional climate as a first-pass heat-loss proxy. A qualified installer should confirm the final model.
Cost
Installation ranges come from a dated NZ pricebook and stay broad because access, pipework, electrical work and system design vary.
Running cost
The estimate uses your electricity rate, daily use and an efficiency assumption. Replace the defaults with your bill and model data when available.
Sources and limits
Keep the estimate current.
Reviewed 15 September 2026. The model and pricebook are in planning beta: useful for comparing options, but still subject to an in-home heat-loss assessment and a written installer quote.