Figure out what any appliance actually costs to run, based on its wattage, how long you use it, and your real electricity rate. The default rate below is the current U.S. national average (18.4¢/kWh per EIA data), but swap in your own rate from a recent bill for an accurate number.
Common Appliance Wattages
Not sure what your appliance actually draws? Check the label or manual for exact numbers, but here are typical ranges to get started.
| Appliance | Typical Wattage |
|---|---|
| Refrigerator (running average) | 100–200W |
| Space heater | 1,500W |
| Window AC unit | 900–1,440W |
| Central AC | 3,000–3,500W |
| Electric water heater | 3,000–4,500W |
| Clothes dryer | 2,000–3,000W |
| Dishwasher | 1,200–1,800W |
| Microwave | 600–1,200W |
| Hair dryer | 1,200–1,800W |
| Desktop computer | 200–400W |
| LED TV | 30–100W |
| LED light bulb | 8–12W |
How This Calculator Works
The math is simple once broken down into three steps:
- Convert watts to kilowatt-hours. Multiply wattage by hours used, then divide by 1,000. A 1,500W space heater run for 2 hours uses 3 kWh.
- Multiply by your rate. That 3 kWh times $0.184 (the national average) comes to about $0.55 for that one session.
- Scale it up. The daily figure gets multiplied by 30 for a monthly estimate, and by 365 for a yearly one, assuming consistent daily use.
The one number that actually changes this calculation the most is your real electricity rate, not the appliance itself. Check a recent bill for your exact rate per kWh, since it can vary significantly by region and utility provider.
Want to cut a specific cost down? Check our Climate & Energy guide for smart thermostats, or the energy monitoring smart plugs article to track actual usage automatically instead of estimating.
Rate data: EIA national average, August 2026. Last Updated: August 2026.