Appliance Energy Calculator

How the calculation works

Energy, kWh = power in W/1,000 × hours × duty cycle/100. Monthly use = daily use × days.

Inputs

• Power, W
• Hours per day
• Duty cycle, %
• Days

Calculation details

A 1,000 W appliance running continuously for 2 hours uses 2 kWh. If its heater is active half the time, this model gives 1 kWh.

For variable-load appliances, rated power is not average power. Use measured average wattage at 100% duty cycle, or rated wattage with an estimated duty cycle.