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Electricity Cost Calculator: What Does an Appliance Cost to Run?
Find what any appliance or device costs to run per hour, day, month and year from its wattage, how long you use it and your electricity rate. Pick a common appliance to fill in typical numbers.
How to calculate electricity cost
Your bill charges for energy in kilowatt-hours (kWh): 1,000 watts running for one hour. Multiply the appliance's watts by the hours it runs, divide by 1,000, then multiply by your rate:
cost = watts × hours ÷ 1,000 × price per kWh
Worked example: a space heater
A 1,500 W space heater on high for 4 hours a day uses 1.5 × 4 = 6 kWh a day. At $0.18 per kWh that is $1.08 a day, $32.40 for a 30-day month, or about $390 a year if it ran every day. Run it only in the coldest three months and it costs about $100 a season.
Typical appliance costs
| Appliance | Typical use | Per month at $0.18/kWh |
|---|---|---|
| Refrigerator (modern) | about 1.5 kWh a day | about $8 |
| Window AC, 900 W | 8 hours a day | about $39 |
| Central AC, 3 ton | 8 hours a day | about $150 |
| Electric clothes dryer | 1 hour a day | about $16 |
| TV, 100 W | 4 hours a day | about $2 |
| LED bulb, 10 W | 5 hours a day | about $0.27 |
| EV, Level 2 charging | 2 hours a day | about $78 |
Finding the right numbers
- Watts are on the nameplate or charger label. If it lists amps instead, multiply amps × volts (120 V for most US outlets).
- Appliances with a thermostat or compressor (fridges, ACs, heaters on low) cycle on and off, so their average draw is lower than the nameplate. A plug-in energy meter gives the real number.
- Your rate is on your electric bill: divide the total charge by the kWh used to include delivery fees. The US average is around 16 to 18 cents per kWh, but ranges from about 11 cents to over 40 cents by state.
Sizing an air conditioner? See the BTU calculator. Planning for outages? Try the generator size calculator.
Frequently asked questions
How much does it cost to run a 1,500 watt space heater?
At $0.18 per kWh it costs 27 cents an hour on high. Four hours a day is about $32 a month.
How do I calculate kWh from watts?
Multiply watts by hours of use and divide by 1,000. A 100 W TV used for 5 hours uses 0.5 kWh.
What is the average cost of electricity per kWh?
The US average residential rate is around 16 to 18 cents per kWh, ranging from about 11 cents in some states to over 40 cents in Hawaii. Your bill shows your exact rate.