Power, runtime, duty cycle, energy and electricity cost
Convert Watts to kWh and kWh Back to Average Watts
Calculate daily, monthly and annual energy from appliance watts, operating time, quantity and duty cycle. Reverse mode finds the average watts represented by a known kWh total, while cost mode applies an entered electricity rate.
W → kWh
$ COST
$ COST
Power and usage
Energy and cost result
Watts to kWh formula
Energy in kilowatt-hours equals watts multiplied by hours and divided by 1,000. Quantity and duty cycle multiply active energy. Standby energy uses the remaining hours in each day. Cost equals total kWh multiplied by the entered rate.
kWh to watts
Reverse mode divides known kWh by the total active device-hours and multiplies by 1,000. The answer is average active watts per device, not peak or startup power.
Is kW the same as kWh?
No. Kilowatts measure power at a moment; kilowatt-hours measure energy accumulated over time.