Electricity Cost Calculator
Estimate your energy usage and costs.
Electricity Cost Calculator
Enter an appliance wattage, how many hours a day it runs and your electricity rate. The calculator estimates daily, monthly and yearly energy use and cost.
How the estimate works
Energy (kWh) = watts × hours ÷ 1,000. Multiply by your rate per kWh for cost. The calculator extends the daily figure to 30 days and 365 days.
Where the estimate goes wrong
The rated wattage on a label is the maximum draw. Appliances with thermostats or compressors (fridges, space heaters, air conditioners) cycle on and off, so real use is often 30 to 60 percent of the label figure. Standby draw on electronics adds a few watts around the clock. For real numbers, a plug-in power meter that logs kWh over a day or a week is the only reliable method; see the energy and electrical testing category.
Finding your rate
Your bill shows a per-kWh energy charge. If it shows tiers or time-of-use periods, use the rate that applies when the appliance runs. Add delivery charges if they are billed per kWh.