What your appliances cost to run

Ranked by what they cost to run in a year. The order surprises most people: the appliance that costs the most is rarely the one that draws the most power, it is the one that runs the longest.

Open the appliance calculator

There are two kinds of appliance and confusing them is how most appliance calculators go wrong.

Things you switch on

A kettle, a heater, a dryer, an oven. These draw their rated power the whole time they are on, so the maths really is watts times hours, and the rating is the whole story. A 2,400 W fan heater costs 2.4 times as much per hour as a 1,000 W one, exactly as you would expect.

Things that cycle on and off by themselves

A fridge, a freezer, a spa. The compressor runs a fraction of the time, decided by the thermostat, the insulation and how warm the room is. A 150 W fridge does not use 150 W all day — it uses about 450 kWh a year, which works out at an average draw closer to 50 W. For these, the only useful number is the measured annual figure from the Energy Rating scheme, and any calculator that asks you how many hours a day your fridge runs is telling you it does not understand refrigerators.

Our calculator handles the two differently and shows you which is which.

A fan heater running five hours a day costs about $477 a year in New South Wales. Multiply the same five hours across all 365 days, as many published figures quietly do, and you get $1,450 — a figure three times too high for an appliance nobody switches on in February.

Every heater, cooler and fan on this site carries the number of days a year it is actually used: about 120 for heating, 90 for cooling, 300 for a pool pump. It is a small thing that makes a large difference to the ranking, and it is adjustable if your household is different.

This is the most expensive misunderstanding on the whole list, and the table above contains the proof of it.

A portable fan heater costs about $30 and turns electricity into heat at exactly 100% efficiency. So does an oil column heater, and so does every other resistive heater sold in Australia. It is not possible to do better than 100%, and no manufacturer claims otherwise — which is why the boxes talk about thermostats and timers and oscillation rather than about efficiency.

A reverse cycle split system does not make heat. It moves heat that is already outside into the room, and moving heat takes far less energy than making it. On our figures a 3.5 kW split system delivers a season's heating for $189. A fan heater doing a comparable job in one room over the same four-month season costs $477, and an oil column heater $397.

So the $30 heater costs about two and a half times as much to run as the split system, every winter, for as long as you own it — a difference of about $288 a year in one room. A split system costs around $2,600 supplied and installed, so on those figures it takes roughly nine years of heating one room to pay the difference back. That is a real payback rather than a good one, and it is worth being straight about: the case for the split is much stronger if you are heating more than one room, if you would use it for cooling in summer as well, or if you are replacing the heater anyway.

What is not in doubt is the direction. Over ten years the fan heater costs about $2,880 more to run than the split does — more than the split costs to install. The plug-in heater is the right answer for a spare room used four nights a year and the wrong answer for anything you heat regularly, which is the opposite of what the purchase price suggests.

The same logic is why the heating and cooling module exists, and it is worked through properly there — including what happens when you scale it up from one room to a whole house. What heating and cooling actually costs.

Kitchen appliances are where the gap between what people worry about and what actually costs money is widest. Almost nobody thinks about the oven and almost everybody thinks about the kettle.

Boiling a full kettle ten times a day is a smaller annual cost than running a middling fridge, because a kettle draws a lot of power for ninety seconds and a fridge draws a little continuously for a year. Time on is what costs money; the number on the plate is only half the calculation, and it is the half that gets all the attention.

Where there is a real saving in an Australian kitchen it is in which box you heat the food in, not in how often you boil water:

• Microwave, about $29 a year. It heats the food and nothing else, which is why it wins on every comparison and always has.
• Air fryer, about $72 a year. Effectively a small fan oven. Its advantage is not the fan, it is the volume — a fraction of the air to heat, and no ten-minute preheat.
• Electric oven, about $145 a year. Heats a large insulated box to cook something small in the middle of it. For a tray of vegetables that is fine; for reheating one portion it is the most expensive option in the room.

That is roughly $116 a year between the extremes — not life-changing, but it is free, it needs no purchase, and it is about the same as switching every standby device in the house off at the wall, which is a great deal more effort.

Ranked by what each one saves a year at your state's rate. These are changes with a real number attached, not general advice about switching things off at the wall.