Electricity Cost Calculator
Calculate the electricity cost of running any device based on wattage, usage hours, and your rate.
Electricity Cost Calculator
Calculate the electricity cost of running any device based on wattage, usage hours, and your rate.
Real-World Examples
1500W, 5 hrs/day, 30 days at $0.12/kWh
225 kWh, $27.00
500W, 4 hrs/day, 30 days at $0.15/kWh
60 kWh, $9.00
10W, 8 hrs/day, 365 days at $0.12/kWh
29.2 kWh, $3.50
Common Mistakes to Avoid
Forgetting to divide by 1000 to convert watts to kilowatts
Fix: Electricity is billed in kilowatt-hours (kWh), not watt-hours. Always divide watt-hours by 1000 before multiplying by the rate.
Using the device's maximum wattage instead of average
Fix: Many devices draw less than their rated power in normal use. A PC rated at 500W might average 200W while browsing. Use a watt meter for the most accurate figure.
Confusing the rate units
Fix: Electricity rates are quoted per kWh (kilowatt-hour), not per watt-hour. A rate of $0.12 means $0.12 per kWh, which is $0.00012 per Wh.