Appliance Running Cost Calculator
What each thing in your house costs per year
Build a list of what is plugged in, and see the annual running cost of each item ranked worst to best. The usual result is that two or three loads account for most of the bill, and everything else is noise.
What is plugged in
Hours are actual running time, not hours switched on. A fridge is plugged in for 24 hours and its compressor runs for about eight.
| On | Appliance | Watts | Hours/day | Standby W | $ / year |
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Worst offenders
Ranked by annual cost. In most homes the top three account for the bulk of the bill and everything below them is rounding error.
Totals
- Annual consumption
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- Daily consumption
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- Appliances counted
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- Share from the top three
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Show the working
How this is calculated
Every assumption is listed so you can disagree with it. If a figure here is wrong, tell us and we will fix it.
The model
There is no cleverness here, and that is the point:
running kWh/yr = watts × hours per day × 365 / 1000 standby kWh/yr = standby watts × (24 − hours per day) × 365 / 1000 cost = (running × rate) + (standby × standby rate)
Standby is charged only for the hours the appliance is not running, so nothing is double-counted.
Hours means run time, not switched-on time
This is where most estimates go wrong. Anything with a thermostat — fridge, freezer, air conditioner, well pump, electric water heater — cycles. Its compressor or element is drawing power for a fraction of the day even though it is available all day. A fridge plugged in for 24 hours typically runs for six to nine, depending on ambient temperature and how often the door opens.
Enter the run time, not the plugged-in time, or you will overstate those loads by a factor of three or more.
Where the defaults come from
The preset wattages are mid-range figures for common equipment, close to the values the Department of Energy publishes for household appliance estimation. They are a starting point, not a measurement of your appliance.
Your own equipment carries a nameplate label with its rated draw, though rated draw is usually the maximum rather than the typical. The honest way to settle an argument about a specific appliance is a plug-in energy meter, which costs about the price of one month of the thing you are arguing about.
What this is useful for
Deciding where to spend attention. The common finding is that heating, cooling, water heating and one or two resistive loads dominate, while the collection of small electronics people worry about adds up to very little. If your top three are not the things you assumed, that is the result — and it usually redirects the budget somewhere more productive than replacing light bulbs that are already LED.
What this leaves out
No seasonal variation, no time-of-use tariff modelling, no demand charges, no power factor, and no efficiency degradation as equipment ages. Heating and cooling in particular vary enormously by month; for those, the sizing and insulation calculators are the better tools.
Sources
The constants and default values above come from these public sources. Every one is free to read and none of them are ours — check the figures against them.
- DOE — Estimating Appliance and Home Electronic Energy Use The watts-times-hours method used here, plus typical wattages for common equipment.
- EIA — Residential Energy Consumption Survey What end uses actually dominate US household electricity, against which to check your own ranking.
- ENERGY STAR — Product Finder Measured annual consumption for specific models, better than any generic preset.
- LBNL — Standby Power Summary Table Measured standby draw for a long list of devices, if you want real numbers rather than our defaults.
Built by Vano Gelashvili
Vano Gelashvili is a software developer who builds the calculators on this site. He is not an HVAC engineer, and says so on every page: what he brings is the arithmetic, worked openly against published data.