See what every appliance is really costing you — per hour, day, month and year.
Pick an appliance or your EV charger, adjust the power, usage and electricity price, and see the estimated cost instantly. No account is required. The calculation runs in your browser; Google ads support the site.
Energy use around the home
More energy use around the home
Plug-in heaters run at 1,500W on high — there is no low-power mode that still heats a room.
Running a space heater at 1,500W for 5 h a day costs about
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From "what's that thing costing me?" to an answer in seconds
No nameplate hunting, no spreadsheet — we fill in the hard numbers and show the assumption behind every one.
Pick your appliance
Choose from 54 presets — space heater, dryer, pool pump, fridge, gaming PC, Level 2 EV charger and more. We fill in a typical wattage so you never need the nameplate.
Set your rate and your usage
Use your region's average price or type the exact per-kWh figure from your bill, then set the usage in the terms that fit the appliance — hours a day, cycles a week, or miles driven.
See the real cost
Cost per day, month and year, with the assumption it rests on stated next to it — plus a worked example of what one specific change would do. Switch to whole-home mode to rank everything biggest-first.
The honest number, not a sales funnel
No account wall and no lead form — a calculator whose assumptions are on the page, so you can check them.
No signup, no email
No account, no lead form, no newsletter wall. It works the instant the page loads, and the calculation happens on your device. The one exception is a share link you choose to create, which carries your figures in the address — the privacy notice explains it.
Sourced and dated
Every calculator states its price source, period and retrieval date, and says which figures are confirmed and which are carried forward. See the methodology.
A model that fits
A fridge is costed on how much of the day it runs, a dishwasher per load, an EV on miles driven. One formula for all of them produces confident numbers that are quietly wrong.
Savings you can check
Every savings figure names the input that changed, the baseline and the result — and where a product swap cannot save what people expect, the page says so.
How this works
Electricity is billed by the kilowatt-hour, so every answer here comes down to two things: how many kilowatt-hours a day an appliance uses, and what you pay per kilowatt-hour. The second is on your bill. The first is where most running-cost figures go wrong, because a nameplate wattage multiplied by hours only describes an appliance that draws steady power the whole time it is on.
Most do not. A refrigerator is plugged in all day and runs for about a third of it. A dishwasher uses energy per load, not per hour. A heat pump moves three to four units of heat per unit of electricity. An electric car's charging cost is set by the miles you drove, not the rating of the charger. So each appliance here declares which of 6 usage models it belongs to, and the calculator asks for the inputs that model actually needs. The methodology page sets out all of them, and their limits.
The single-appliance view answers the literal question — "what does my space heater cost?" — but the real question is usually "where is my bill going?" That is what whole-home mode is for: list everything you run and WattDollar ranks them biggest-first, so the pool pump or the old garage fridge stops hiding behind the things you were worried about.
Common questions
How do you work out the cost?
Every calculation reduces to kilowatt-hours used multiplied by your price per kWh. A 1,500W heater run for 5 hours a day uses 7.50 kWh a day, which at $0.1816/kWh is $1.36 a day and $41.46 a month. How the kilowatt-hours are worked out depends on the appliance — a fridge cycles, a dishwasher runs per load, an electric car is costed on miles driven. See the methodology for all six models.
Where do I find my electricity rate?
It is the price per kilowatt-hour on your bill. We pre-fill a regional average — currently $0.1816/kWh for the U.S. — but that is a benchmark, not your tariff. For the accurate figure, divide the total on a recent bill by the kilowatt-hours it covers and type that in; it captures the fixed charges and taxes an average leaves out.
I don't know my appliance's wattage — is that a problem?
No. Pick the closest match and we fill in a typical figure for that kind of appliance, with its usual range shown. If you want to be exact, the real number is usually printed on a label on the appliance or in its manual, and you can type it in.
Why doesn't the fridge run 24 hours?
Because it does not run 24 hours — its compressor cycles on and off to hold temperature, for roughly a third of the day. The fridge calculator is built on that: you set the running power, the hours it is plugged in and the share of that time it actually runs, which is why it lands on the real one to two kilowatt-hours a day rather than a figure six times too high.
Is this free, and what is the catch?
It is free and there is no account. The site is paid for by Google ads on the calculator and guide pages, and some product links may earn a commission — each is labelled where you meet it. Neither changes a number the calculator produces. What you type stays in your browser unless you create a share link, which carries the figures in its address; your rate and appliance list are saved in your browser's local storage so the page remembers them.
Data basis
- Electricity price
- U.S. Energy Information Administration, Electric Power Monthly, Table 5.6.B, June 2026 year to date, released 2026-08-26. Retrieved 2026-09-11. Average residential revenue per kWh. A benchmark average, not a utility tariff — it excludes the fixed charges, tiers, time-of-use windows, taxes and fuel adjustments on a real bill.
- International prices
- rounded typical household tariffs for each market, in that market's own currency unless the row says US$ equivalent. These are planning benchmarks with no single primary source; enter the per-kWh price from your own bill for an accurate figure.
- Last reviewed
- 20 August 2026. Next scheduled review 20 February 2027.
- Corrections
- Think a figure is wrong? Tell us at corrections@watt-dollar.com and see our corrections policy.