Appliance Wattage Calculator
Enter your appliance wattage, daily usage hours, and local electricity rate to see exactly how much power it uses and what it costs per day, month, and year. Choose a preset appliance for a typical wattage or type your own. Results update as you type.
How to calculate appliance electricity cost
The core formula is simple: multiply the appliance wattage (in kilowatts) by the number of hours used, then multiply by your electricity rate in dollars per kilowatt-hour. Formally: Cost = (Watts / 1,000) x Hours x Rate. For example, a 1,500-watt space heater running 4 hours a day at $0.16/kWh costs (1.5 kW x 4 h x $0.16) = $0.96 per day, about $29 per month, and around $350 per year. Most home appliances draw between 10 watts and 5,000 watts. Heating, cooling, and drying equipment sit at the high end and typically account for more than half of a typical household electricity bill.
Finding your appliance wattage
The rated wattage appears on a label on the back or bottom of most appliances, on the power brick or cord, or in the product manual. For appliances that list amperes and volts instead of watts, multiply them: Watts = Amps x Volts. In North America the standard outlet voltage is 120 V (and 240 V for large appliances), so a device drawing 10 A at 120 V uses 1,200 W. Note that the rated wattage is the maximum draw; many appliances cycle or dim, so actual average consumption is lower. Refrigerators, for instance, cycle their compressor and use roughly 40-60% of their rated draw on average.
Reducing your appliance electricity bill
The quickest wins come from the appliances with the highest wattage or longest daily run times. Electric water heaters and HVAC equipment typically dominate. Lowering your water heater thermostat from 140 F to 120 F can cut its energy use by 4-22%. Adding a timer to electric baseboard heaters or portable space heaters prevents them running overnight. For refrigerators and freezers, ensuring door gaskets seal tightly and coils are clean can restore efficiency without replacing the unit. LED lighting replacements save roughly 75% compared with incandescent bulbs, but because bulbs are low-wattage they represent a smaller slice of the total bill than heating or cooling equipment.
Understanding kilowatt-hours and electricity bills
Your utility bill charges in kilowatt-hours (kWh) - the energy used by a 1,000-watt device for one hour. The US average residential rate was about $0.16/kWh in 2024, but rates range from under $0.10/kWh in states with abundant hydropower to over $0.30/kWh in Hawaii and parts of the Northeast. Your exact rate is on your bill; divide the total charge by the total kWh consumed to get the effective blended rate including fixed charges. Time-of-use rates charge more during peak hours (typically 4-9 pm on weekdays), so shifting large appliance loads - like running the dishwasher or charging an EV overnight - can noticeably lower your bill.
Typical wattage ranges for common household appliances
| Appliance | Typical wattage (W) | Notes |
|---|---|---|
| Refrigerator | 100-400 | Cycles on/off; actual draw is ~50% of rated |
| Chest/Upright Freezer | 30-100 | Highly efficient modern models |
| Dishwasher | 1,200-2,400 | Heating element dominates |
| Washing Machine | 300-500 | Hot-water wash increases draw |
| Clothes Dryer (electric) | 4,000-6,000 | One of the largest home loads |
| Electric Oven/Range | 2,000-5,000 | Depends on elements in use |
| Microwave | 600-1,200 | Running wattage; standby is ~3 W |
| Window AC | 500-1,500 | Varies by BTU rating |
| Central AC | 2,000-5,000 | Per ton of cooling capacity |
| Space Heater | 750-1,500 | Typically runs at rated wattage |
| Electric Water Heater | 3,000-5,500 | Recovers then cycles off |
| LED Bulb | 4-15 | Replaces 40-100 W incandescent |
| Desktop Computer + Monitor | 150-400 | Idle vs. full load varies widely |
| Laptop | 20-100 | Much less than desktop |
| LED Television (55") | 60-130 | OLED uses more than LCD |
| Gaming Console | 100-200 | Newer consoles in active play |
| Hair Dryer | 1,200-1,875 | High-heat setting |
| EV Charger (Level 2) | 3,300-19,200 | Depends on EVSE and car |
Actual wattage varies by model, age, and usage pattern. Check the label or manual for your specific appliance.
Frequently asked questions
How do I find the wattage of my appliance?
Check the label on the back or bottom of the appliance, the power cord, or the product manual. The label usually shows watts (W) or amps (A) and volts (V). If you see amps and volts but not watts, multiply them: Watts = Amps x Volts. For a North American 120-volt outlet, a 10-amp appliance draws 1,200 watts.
Why does my electricity bill show more than this calculator predicts?
A few factors can cause a higher bill: the calculator uses the rated wattage rather than measured draw, which can differ; your bill may include fixed charges, taxes, and distribution fees on top of the per-kWh rate; and standby or phantom loads from devices left plugged in all add up over time. To get the most accurate reading, use a plug-in watt meter (such as a Kill A Watt) to measure actual consumption.
What is a kilowatt-hour (kWh)?
A kilowatt-hour is the energy consumed by a 1,000-watt device running for one hour. One kWh equals running a 100-watt light bulb for 10 hours, or a 1,000-watt microwave for 60 minutes. Your utility bills you per kWh, and the US average residential price is roughly $0.16/kWh, though it varies widely by state and provider.
How much does it cost to run a refrigerator all year?
A modern full-size refrigerator typically draws 100-400 watts but cycles its compressor, so actual average consumption is roughly 150 kWh per month (about 1,800 kWh/year). At $0.16/kWh that works out to roughly $24/month or $288/year. Older models can use two to three times more. Check the ENERGY STAR label for your specific model's annual kWh estimate.
Which home appliance uses the most electricity?
Heating and cooling equipment top the list. A central air conditioner (3,500 W), electric furnace (10,000 W), or electric clothes dryer (5,000 W) can each dwarf every other appliance combined when run regularly. Electric water heaters (4,500 W) also rank high. Lighting and small electronics, while numerous, typically contribute far less because their wattage is low.
Does the calculator account for appliances that cycle on and off?
Yes - the daily usage hours you enter represent average active running time, not time plugged in. For a refrigerator that runs about 8 hours per day on its compressor, enter 8 h/day even though it is plugged in 24 hours. The "days per week" field handles seasonal appliances: enter 5 days for a window AC you run on weekdays only, and the calculator averages its daily cost over the full week.
What is the average US electricity rate?
The US Energy Information Administration reported an average residential rate of about $0.16/kWh in 2024. Rates vary significantly: Louisiana and Idaho often average below $0.10/kWh, while Hawaii and Connecticut can exceed $0.25/kWh. Your actual rate is on your utility bill; divide total charges by total kWh for the blended effective rate.