Electricity Cost Calculator
This electricity cost calculator shows what any device costs to run. Enter its wattage, how many hours a day you use it, and your rate per kWh, and you'll get the cost per day, month, and year, plus the energy it uses. Tap an appliance preset if you don't know the watts, and change the rate to match your bill. It's free, private, and updates as you type.
- Cost per day, month, year
- Watts or kilowatts
- Your own rate
- Appliance presets
- kWh used
Last updated June 17, 2026 US average rate near $0.17/kWh Reviewed by the Calcowa team
Enter power, hours, and rate above 0.
A device's wattage is on its label or in the manual. The default rate is near the US average.
1 kW × 5 h × 30 days × $0.17 = $25.50
How do I calculate electricity cost?
Electricity is billed by the kilowatt-hour, which is a 1,000-watt load running for one hour. So the recipe is simple: convert watts to kilowatts by dividing by 1,000, multiply by the hours of use to get kilowatt-hours, then multiply by your rate. A 1,000-watt heater run 5 hours a day uses 5 kWh daily, and at 17 cents that's 85 cents a day, about 25 dollars a month. This electricity cost calculator chains those steps and scales them to a day, a month, and a year, so you'll see the real impact of leaving something on rather than guessing at the bill.
Pricing an appliance, step by step
Here's a 1,000-watt heater run 5 hours a day at a 17-cent rate. It's the same path the tool runs for any device:
- 1
Convert to kilowatts1,000 watts divided by 1,000 is 1 kilowatt of draw.
- 2
Multiply by hours1 kW times 5 hours is 5 kilowatt-hours used in a day.
- 3
Multiply by the rate5 kWh times 17 cents is about 85 cents for the day.
- 4
Scale it out85 cents a day is roughly 25 dollars a month and 310 dollars a year.
Typical appliance wattages
Here are rough wattages and a monthly cost estimate at 17 cents per kWh. Use them as a starting point, then tap a preset or type your own numbers for an exact figure. They're rough because real use varies, so if you're chasing a high bill, it's worth metering the big appliances to see what they're really pulling.
| Appliance | Watts | Typical use | Est. per month |
|---|---|---|---|
| LED bulb | 10 | 5 h/day | $0.26 |
| TV | 100 | 5 h/day | $2.55 |
| Refrigerator | 150 | 24 h/day | $18.36 |
| Window AC | 1,500 | 8 h/day | $61.20 |
| Space heater | 1,500 | 5 h/day | $38.25 |
Frequently asked questions
Turn the device's wattage into kilowatts by dividing by 1,000, multiply by the hours you run it, and you've got the kilowatt-hours used. Multiply that by your rate per kWh for the cost. A 1,000-watt heater for 5 hours a day uses 5 kWh, so at 17 cents it's about 85 cents a day. This electricity cost calculator runs all of that the moment you type.
A 1,000-watt appliance draws 1 kilowatt, so each hour costs one times your rate. At 17 cents per kWh that's 17 cents an hour, about 85 cents over 5 hours, and roughly 25 dollars a month at that daily use. Swap in your own rate and hours above and you'll see the exact figure, since both vary a lot by home and habit.
It's on your power bill, usually labeled as the price per kWh or per kilowatt-hour, and the US average sits around 16 to 18 cents. Some plans charge more during peak hours or above a usage tier, so if your bill shows several rates, use the one that matches when the device runs. The tool defaults near the average, and you can change it.
Anything that makes heat or runs constantly: air conditioners, electric heaters, water heaters, clothes dryers, and the fridge, which sips power but never switches off. Phone chargers and LED bulbs barely register. The reference table below lists typical wattages, so you can spot the big draws and see which ones are worth cutting back.
Target the high-wattage, long-running devices first, since they move the bill most. Trimming an hour off the air conditioner saves more than unplugging a dozen chargers. Switching incandescent bulbs to LED, running the dryer less, and sealing heating or cooling losses all add up. Use the calculator to price a change before you make it, so you'll know the payoff.
Yes to both. There's no sign-up, no limit, and nothing to install, since it runs in your browser. The numbers you enter stay on your device and aren't sent anywhere. Bookmark it and you'll have a quick way to price any appliance before you buy it or to settle a debate about what's driving the bill.
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