Electricity Cost Calculator
See how much any appliance costs to run per hour, day, month and year – from space heaters and air conditioners to gaming PCs and EV chargers.
Formulas shown on this page · Last reviewed October 2026
Electricity cost formula
kWh per day = watts × hours per day ÷ 1,000
cost = kWh × rate ($/kWh)
Typical running costs at $0.18/kWh
| Appliance | Watts | Use | Per month |
|---|---|---|---|
| Space heater | 1,500 | 6 h/day | $49 |
| Window AC | 900 | 8 h/day | $39 |
| Refrigerator | 150 avg | 24 h/day | $20 |
| Gaming PC | 400 | 4 h/day | $9 |
| LED TV 55" | 100 | 5 h/day | $3 |
Ways to cut the bill
- Heating and cooling are usually the biggest loads – a smart thermostat and sealing drafts pay off fastest.
- Check whether your utility offers time-of-use rates and run dryers, dishwashers and EV charging off-peak.
- Unplug or use smart strips for devices with high standby draw.
Cost to run common appliances
Space heater · Window AC · Portable AC · Central AC · Refrigerator · Chest freezer · Dehumidifier · Electric water heater · Clothes dryer · Dishwasher · Washing machine · Electric oven · Gaming PC · TV · Ceiling fan · Hot tub · Pool pump · EV Level 2 charger · Electric blanket · Mini split
Frequently asked questions
How do I calculate electricity cost?
Multiply the appliance wattage by hours of use, divide by 1,000 to get kWh, then multiply by your rate per kWh. A 1,500 W heater running 6 hours uses 9 kWh – about $1.62 a day at $0.18/kWh.
How much does it cost to run a space heater?
A 1,500 W space heater costs about $0.27 per hour at $0.18/kWh – roughly $49 a month if used 6 hours a day.
What is the average electricity rate in the US?
The average residential rate is about 17–18 cents per kWh, ranging from around 11 cents in some central states to over 30 cents in California and New England, and over 40 cents in Hawaii.
Where do I find an appliance’s wattage?
Check the label on the back or bottom of the device, the power adapter, or the manual. If only amps are listed, multiply amps by 120 volts.