Heating efficiency
Heat pumps are common in New Zealand homes because they move heat rather than create it directly. Use the unit’s electrical input and the cents-per-kWh rate from your own power plan for the running-cost estimate.
Change every default to reflect your appliance.
Estimated running cost
$670.14
per yearEnergy / year
1,971 kWh
Per hour
$0.08
0.23 kWh
Per day
$1.84
5.4 kWh
Per week
$12.85
37.8 kWh
Per month
$55.88
164.36 kWh
Per year
$670.14
1,971 kWh
Compared with a 2,000 W resistance heater
55% lower estimateThe result estimates the variable electricity cost for the heat pump itself at the entered electrical input, daily hours and power rate. It does not represent the home’s complete electricity bill or promise a particular room temperature.
Electrical input in watts is divided by 1,000 to convert it to kilowatts, then multiplied by running hours and the electricity price per kWh. Heating output and COP explain efficiency but are not added to the electricity consumed.
A 900 W electrical input used for six hours consumes 5.4 kWh before any cycling adjustment. At 34 cents per kWh, that is about $1.84 for the day.
Electrical input is the value that drives the electricity cost. Replace the example electricity rate and usage with figures from your appliance and current plan.
The result estimates the variable electricity cost for the heat pump itself at the entered electrical input, daily hours and power rate. It does not represent the home’s complete electricity bill or promise a particular room temperature.
Calculation method
Electrical input in watts is divided by 1,000 to convert it to kilowatts, then multiplied by running hours and the electricity price per kWh. Heating output and COP explain efficiency but are not added to the electricity consumed.
Worked example
A 900 W electrical input used for six hours consumes 5.4 kWh before any cycling adjustment. At 34 cents per kWh, that is about $1.84 for the day.
The default rate is a starting point only. Check a current bill from your retailer—such as Contact, Meridian or Genesis—for the cents-per-kWh rate that applies to your plan. Tariffs, lines charges and heating needs can differ between Auckland, Wellington, Christchurch, Otago and provincial networks, so your own bill is a better input than a national example. Fixed daily charges and other appliances remain separate from this estimate.
Typical values and guidance are informed by EECA and MBIE electricity prices.
For a better input, see how to choose an NZ electricity rate and read an appliance energy label.
For a heating comparison, read the heat pump vs electric heater cost NZ guide.
Not necessarily. Running cost depends on electrical input, hours, outdoor temperature, thermostat setting, insulation and your electricity rate. A heat pump can deliver more heat per unit of electricity than a resistance heater, but long operating hours or a hard-to-heat room can still produce a significant bill.
This calculator estimates electricity running cost only. It does not estimate the purchase price, installation, servicing or repairs, which vary by system size, property and installer.
No. Output and electrical draw change with temperature, settings and compressor operation. Use measured electrical input when available.
No. COP compares delivered heat with electrical input. Running cost is driven by electrical energy consumed, not heating output alone.
No. It estimates variable energy cost for this appliance and excludes fixed daily charges and all other household electricity use.
Colder outdoor temperatures, heat loss and longer running hours can make the unit work harder. Actual performance also varies by model and installation.