How Much Does It Cost to Run This Appliance?
Almost everything plugged into a wall has a price per hour, and for most appliances it is either much smaller or much larger than people expect. All you need to work it out is three numbers: how many watts the appliance draws, how long it runs, and what you pay for a kilowatt-hour. The calculator below does the arithmetic for you and shows the cost per hour, per day, per month and per year. Start with the quick answers if you just want the headline figures.
Quick answers
These examples use the US default rate of $0.173/kWh in the calculator. The per-day cost is the energy used in a day multiplied by that rate, rounded to the nearest cent.
| Appliance | Assumed use | kWh per day | Cost per day |
|---|---|---|---|
| Space heater | 1,500 W for 6 h/day | 9.00 | $1.56 |
| Central AC | 3,500 W for 8 h/day | 28.00 | $4.84 |
| Tumble dryer | 3,000 W for 1 h/day | 3.00 | $0.52 |
| Fridge | 150 W running 24 h at 35% duty cycle | 1.26 | $0.22 |
| LED bulb | 10 W for 5 h/day | 0.05 | $0.01 |
The pattern matters more than any single row. Heating and cooling dominate, a fridge is cheap because its compressor cycles on and off, and modern lighting costs almost nothing to run.
Appliance Electricity Cost Calculator
Choose a preset or enter your own watts, then add how long the appliance runs. Results update as you type, and the Calculate button recalculates on demand.
Duty cycle is the share of that time the appliance actually draws full power.
Enter watts and hours per day to see your costs.
Per hour: —
Per day: —
Per month: —
Per year: —
The formula
kWh = Watts × hours ÷ 1,000
Cost = kWh × rate
A watt is a measure of power at a single moment: how fast an appliance is using energy right now. A kilowatt-hour is a measure of energy over time: how much it has actually used. Think of watts as the speed of water coming out of a hose and kilowatt-hours as the water collected in the bucket. A 1,000 W appliance running for one hour fills the bucket with exactly 1 kWh. Run it for half an hour and it uses 0.5 kWh, however powerful it is. That is why both numbers matter, and why a small appliance left on all day can quietly cost more than a powerful one used for ten minutes. The calculator extends the basic formula with duty cycle and quantity, so cycling appliances and multiple identical items are counted honestly.
Worked example
Take a 1,500 W space heater used for 6 hours a day. Step 1: multiply the watts by the hours — 1,500 × 6 = 9,000 watt-hours. Step 2: divide by 1,000 to convert to kilowatt-hours — that is 9 kWh per day. Step 3: multiply by the rate — 9 × $0.173 = $1.557, or $1.56 per day. Step 4: scale it up. That is $1.56/day, about $47.42/month and about $569/year, depending on how the daily figure is rounded. A heater that feels like a small comfort on a cold evening is, over a winter, one of the most expensive things in the house to run.
Typical wattages
These are the typical figures used by the presets in the calculator. Real models vary, sometimes by a lot, so treat them as a sensible starting point rather than a promise.
| Appliance | Typical watts |
|---|---|
| Space heater | 1,500 W |
| Central AC | 3,500 W |
| Tumble dryer | 3,000 W |
| Refrigerator | 150 W |
| Washing machine | 500 W |
| Oven | 2,000 W |
| Dishwasher | 1,200 W |
| Microwave | 1,000 W |
| TV | 80 W |
| Computer | 200 W |
| Fan | 75 W |
| LED bulb | 10 W |
The rating plate or manual gives the exact figure for your model. If the plate lists amps and volts instead of watts, multiply them together: amps × volts = watts. A plate showing 12 A and 120 V, for example, means a maximum draw of 1,440 W.
Why your bill will differ
This calculator estimates the energy charge — the cost of the kilowatt-hours themselves. Your real bill adds several things on top, which is why it will almost always be higher than the figure here.
Duty cycle. Many appliances do not draw full power continuously. A fridge is plugged in for 24 hours, but its compressor cycles on and off to hold temperature, so it might only draw its rated watts about 35% of the time. Thermostats do the same for heaters and air conditioners once a room reaches temperature.
Standing and supply charges. Most tariffs charge a fixed amount per day just for being connected, whether you use anything or not. In the UK that standing charge is 53.68p per day under the price cap figures used on this page. In Australia the daily supply charge is roughly AUD $0.80–1.50 per day. Neither is included in the per-kWh figures here.
Taxes and tariff structure. Sales tax or VAT may be added, and many households are not on a flat rate at all. Tiered tariffs charge more once you pass a usage threshold, and time-of-use tariffs charge more at peak hours and less overnight. If your tariff works that way, the hour you run an appliance can change its cost as much as the appliance itself.
Electricity rates by country
| Country | Preset rate | Source and date |
|---|---|---|
| United States | $0.173/kWh | EIA average residential price, 17.30¢ in 2025 |
| United Kingdom | £0.2635/kWh | Ofgem price cap, Oct–Dec 2025, plus 53.68p/day standing charge |
| Canada | CAD $0.16/kWh | Mid default; Hydro-Québec April 2025 city range, Montréal 8.29¢ to Calgary 22.90¢ |
| Australia | AUD $0.32/kWh | Finder average ~31–32¢, state range roughly 24–43¢ |
Two warnings belong with this table. First, the UK cap changes quarterly, so check your bill for the unit rate and standing charge that apply right now rather than relying on any preset, including this one. Second, a single Canada-wide rate is misleading: the Hydro-Québec April 2025 comparison runs from Montréal at 8.29¢ to Calgary at 22.90¢, so a Canadian household can pay nearly three times as much per kilowatt-hour depending on its city. Australia varies widely by state too, roughly 24–43¢. Your own bill always overrides these presets.
Ways to cut the cost
Start where the money is: heating and cooling. Run a space heater for fewer hours, heat only the room you are in, and fix the draughts that let the heat escape. For air conditioning, clean filters, shade sunny windows and raise the thermostat setting by a degree or two. Wash and dry in full loads, use cooler wash cycles, and clean the dryer lint filter so cycles finish faster. Swap any remaining old bulbs for LEDs — at about $0.01 a day in the table above, lighting is the easiest win of all. Switch appliances off at the wall instead of leaving them on standby, and, if your tariff is cheaper overnight, move the dishwasher and washing machine into those hours.
Finally, look hard at old, inefficient appliances. An ageing fridge or heater can cost far more to run each year than a modern equivalent, and at some point replacing it beats repairing it. Run its running cost here first, then use our Repair vs Replace Calculator to weigh the repair quote against the price and savings of a new model.
Electricity guides
Want the worked examples behind the numbers? These guides take the same method appliance by appliance, at US and UK prices, so you can see exactly where your own electricity bill comes from.
- How Much Does It Cost to Run a Dryer?
- What Uses the Most Electricity in a Home?
- How Much Electricity Does a Refrigerator Use?
- How Much Does It Cost to Run a Washing Machine? — Per-load costs in cold, warm and hot water, and the yearly total for a typical family.
Frequently asked questions
How do I calculate an appliance's running cost?
Multiply the watts by the hours it runs, divide by 1,000 to get kilowatt-hours, then multiply by your rate per kWh. If the appliance cycles on and off, reduce the result by its duty cycle, and multiply by the quantity if you have more than one.
Where do I find the watts?
Look for a rating plate or sticker on the back, underside or inside the door, or check the manual or the label near the power cord. If it lists amps and volts instead, multiply them together: amps × volts = watts.
How much does a 1,500 W heater cost to run?
At the US default rate of $0.173/kWh it uses 1.5 kWh per hour, so about $0.26 per hour. Run for 6 hours a day, that is 9 kWh and about $1.56 per day, roughly $47.42 a month and $569 a year.
Why is my real bill higher than the calculator?
The calculator covers the energy charge only. Your bill also includes standing or supply charges, taxes, and possibly higher tiered or peak-hour rates, and nameplate wattage is a maximum rather than an average draw.
Does a fridge really run 24 hours a day?
It is plugged in and cooling for 24 hours, but its compressor cycles on and off to hold temperature. A duty cycle of about 35% is a realistic setting, which is why a 150 W fridge uses roughly 1.26 kWh a day, not 3.6 kWh.
Is 1 kWh the same as 1,000 watts?
No. A watt is power at a moment, while a kilowatt-hour is energy used over time. Running 1,000 watts for one hour uses 1 kWh, and so does running 100 watts for ten hours.
Disclaimer
Disclaimer: these figures are estimates for the energy charge only. Nameplate wattage is a maximum, not an average draw, so your appliance may use less in normal use. Rates are date-stamped presets that change over time — always check your own bill for the rate, standing charge and taxes that actually apply to you.