CalculateY
Quick Answer
A 1,500-watt space heater running 8 hours per day at $0.16/kWh costs approximately $1.92 per day, $57.60 per month, and $700.80 per year.
Check the label on your device or its manual
U.S. average is approximately $0.16/kWh
Common Examples
| Input | Result |
|---|---|
| 1,500W space heater, 8 hrs/day, $0.16/kWh | $1.92/day, $57.60/month, $700.80/year |
| 100W light bulb, 10 hrs/day, $0.16/kWh | $0.16/day, $4.80/month, $58.40/year |
| 200W TV, 5 hrs/day, $0.12/kWh | $0.12/day, $3.60/month, $43.80/year |
| 2,000W oven, 1 hr/day, $0.16/kWh | $0.32/day, $9.60/month, $116.80/year |
| 60W ceiling fan, 12 hrs/day, $0.14/kWh | $0.10/day, $3.02/month, $36.79/year |
How It Works
The Formula
kWh = (Watts x Hours per Day) / 1,000
Daily Cost = kWh per Day x Electricity Rate
Where:
- Watts is the rated power consumption of the device (found on the device label or in its specifications)
- Hours per Day is the number of hours the device runs each day
- 1,000 is the conversion factor from watts to kilowatts
- Electricity Rate is the cost per kilowatt-hour from your utility bill
Monthly cost is the daily cost times the number of days per month (default 30). Yearly cost is the daily cost times 365 days.
What Is a Kilowatt-Hour?
A kilowatt-hour (kWh) is a unit of energy equal to using 1,000 watts for one hour. It is the standard billing unit for residential electricity. A 100-watt light bulb running for 10 hours uses 1 kWh. A 2,000-watt space heater running for 30 minutes also uses 1 kWh.
Finding Your Electricity Rate
Your electricity rate appears on your monthly utility bill, typically listed as a cost per kWh. In the United States, residential rates range from roughly $0.10 to $0.35 per kWh depending on the state and utility provider. The national average is approximately $0.16 per kWh. Some utilities charge different rates for peak and off-peak hours (time-of-use billing), so the average rate provides the best overall estimate.
Common Appliance Wattages
Typical wattages for common household items: LED light bulb (10W), ceiling fan (60W), laptop (50W), desktop computer (200W), TV (100-200W), refrigerator (150W average), microwave (1,000W), electric oven (2,000W), space heater (1,500W), central AC (3,500W), electric dryer (5,000W). These values represent average consumption; actual wattage varies by model and usage pattern.
Worked Example
For a 1,500-watt space heater used 8 hours per day at $0.16 per kWh: Daily kWh = (1,500 x 8) / 1,000 = 12 kWh. Daily cost = 12 x $0.16 = $1.92. Monthly cost = $1.92 x 30 = $57.60. Yearly cost = $1.92 x 365 = $700.80. The heater consumes 360 kWh per month and 4,380 kWh per year. Switching to a more efficient 1,000-watt heater would reduce yearly cost to $467.20, a savings of $233.60 per year.