Every appliance carries a rating, every utility quotes a rate, and almost nobody puts the two together. It takes one multiplication and it turns a vague worry into a number you can act on.
The arithmetic
Annual kilowatt hours multiplied by your all-in rate per kilowatt hour equals what the thing costs you per year. That is the whole method.
The part people get wrong is the rate. Do not use the number the utility advertises. Take your last bill, divide the total amount you paid by the kilowatt hours you used, and use that. It includes delivery charges, fees and taxes, which are money you actually handed over.
Typical ranges for common household equipment, cross-checked against manufacturer energy labels and US Department of Energy figures. Actual use depends on size, age, efficiency rating and how hard you run it. Multiply by your own all-in rate to get a cost.
Why the order looks like that
Notice what is at the top. Heating water, moving water, and removing moisture from air. All three are moving energy around, and that is expensive. The television at the bottom is doing arithmetic and lighting a panel, which is not.
This is the single most useful pattern in household energy. If a machine changes the temperature or the state of something, it is a large load. If it processes information, it is a small one.
The three that catch people out
The garage refrigerator. An older unit in an unheated space works harder than the same unit in a kitchen, because the warmer the room, the more heat it has to remove. Half empty makes it worse. This one appliance can cost more per year than every light in the house.
The dehumidifier that never stops. It is a small air conditioner. Running one continuously all summer to manage a damp basement is treating a symptom at considerable expense. Finding the water source is cheaper.
The pool pump left on a default schedule. Most are installed running far more hours than the pool needs, because nobody went back and adjusted it after commissioning.
If your utility offers hourly usage data, look at three in the morning. Whatever the house draws while everyone is asleep runs all day too. Multiply that hourly figure by 8,760 and you have your annual baseline, which is often a third of the total bill.
What to do with the number
Once you can price a machine per year, decisions get easy. Replacing something that costs a lot to run pays for itself on a schedule you can calculate. Replacing something that costs very little to run almost never does, no matter how old it is.
That is why the advice to replace an old television for efficiency reasons is weak, and the advice to deal with an old second refrigerator is strong. Same age, completely different arithmetic.
Questions people ask
Where do I find how many kilowatt hours my appliance uses?
The energy label if it has one, the rating plate on the back or inside the door, or the manufacturer's specification sheet. Failing that, a plug-in energy monitor measures it directly for anything on a standard outlet.
Is it cheaper to run appliances at night?
Only if you are on a time-of-use rate. On a flat rate it makes no difference to your bill, though it can reduce strain on the grid.
Does a full freezer use less electricity than an empty one?
Slightly, because the frozen contents hold cold when the door opens. The effect is small and not a reason to buy food you will not eat.
Do old appliances really use that much more?
It depends entirely on the type. Refrigeration has improved substantially, with a modern certified fridge using around a third of what a 1990s one did. A kettle or a lamp has not improved, because there was nothing to improve.
Where these figures come from
- Electricity use in homes US Energy Information Administration
- Certified refrigerators and their rated annual use ENERGY STAR
- Energy Saver, the Department of Energy home efficiency guide US Department of Energy
Figures last checked September 2026.
