HomeGuide
How Much Electricity Does a Household Appliance Use?
Use one simple formula to calculate any appliance's electricity use in kWh and its estimated cost, with worked examples, typical wattages and a free calculator.
This article is for general information. Figures and examples are illustrative and can change; check the linked sources before making decisions.
Short answer: to find out how much electricity an appliance uses, convert its watts to kilowatts and multiply by the hours you use it: kWh = (watts ÷ 1,000) × hours. Multiply the kWh by your price per kWh to estimate the cost. The wattage is usually on the appliance's label or in its manual.
The formula, step by step
- Find the watts (W) on the label or manual. If you only see volts (V) and amps (A), multiply them.
- Divide by 1,000 to get kilowatts.
- Multiply by hours of use to get kilowatt-hours (kWh).
- Multiply by your rate, in dollars per kWh, from your electric bill.
Examples (illustrative numbers)
We use a made-up rate of $0.20 per kWh just as an example; your rate is on your bill. For context, the U.S. Energy Information Administration reported an average residential price of 17.30 cents per kWh for 2025.
| Appliance | Watts | Hours per day | Cost per day at $0.20/kWh |
|---|---|---|---|
| LED bulb | 10 | 5 | $0.01 |
| Laptop | 60 | 8 | $0.10 |
| Microwave | 1,000 | 0.25 | $0.05 |
| Space heater | 1,500 | 6 | $1.80 |
Over 30 days, that space heater would use 270 kWh, or $54 at the example rate. That's why heaters and air conditioners matter far more than a phone charger.
Appliances that cycle on and off
Refrigerators, freezers, air conditioners and thermostat-controlled heaters don't run at full power all day, so multiplying by 24 hours overestimates. For those, use the yearly energy use on the EnergyGuide label, or measure it.
How to measure real use
A plug-in energy meter is an inexpensive device that shows the actual watts and kWh. Your utility's online account may also show daily usage if you have a smart meter. Many electronics also draw a little power in standby; a power strip you can switch off helps.
Once you know what each device costs, focus on the few that matter. For ideas, see how to lower your electric bill.
Frequently asked questions
Where do I find my price per kWh?
On your electric bill. If it shows several charges (supply, delivery, taxes), divide the total by the kWh for an all-in average.
What's the difference between watts and kilowatt-hours?
Watts measure the rate of power; kilowatt-hours measure energy used over time. A 1,000 W appliance running for an hour uses 1 kWh.
Guides by appliance
Once you know the formula, see worked examples for specific appliances:
