Heater vs Reverse-Cycle Air Conditioner Cost Calculator
Compare what it costs to get the same heat from a resistance heater and from a reverse-cycle air conditioner (a heat pump).
Last checked 10/11/2026. Sources: Australian Energy Regulator: The Default Market Offer (tariff caps 2026-27); Essential Services Commission (Victoria): Victorian Default Offer price review 2026-27.
Guide
How the cost is worked out
A resistance heater turns each kWh of electricity into 1 kWh of heat. A reverse-cycle air conditioner moves heat, so each kWh of electricity delivers several kWh of heat. That ratio is the coefficient of performance (COP). Electricity needed = heat wanted ÷ COP.
Example. 2 kW of heat for 6 hours a day over 120 days is 1,440 kWh of heat. A resistance heater uses 1,440 kWh. A heat pump with a COP of 3 uses 480 kWh, a third as much.
COP is an editable assumption
A COP of 3 is an editorial rule of thumb. Real COP changes with the outside temperature and the model; the Energy Rating label and the specification sheet give rated figures. Enter the real figure if you have it.
Using it for cooling
Air conditioners cool the same way. Enter the cooling you need in kW and the unit’s rated efficiency, and ignore the resistance comparison.
What is not included
Installation costs, insulation, daily supply charges and time-of-use rates are not included.
Common questions
Is a reverse-cycle air conditioner cheaper than a heater?
Per unit of heat, yes. At a COP of 3 it uses about a third of the electricity, so it would save about two thirds of the running cost.
What is a good COP?
It depends on the model and the weather. Check the specification sheet or Energy Rating label.
How do I know how many kW I need?
An installer can size it from the room. The tool lets you try different figures.
Does this include gas?
No. It compares two electric options only.
What next?
- Is a heat pump worth the up-front cost? Work out the payback. Energy Upgrade Payback Calculator
- Doing the work yourself? Plan the materials with Handyfig