Power in watts (W) to energy in kilowatt-hours (kWh) calculator and calculation formula.
Enter the power in watts, and the consumption time period in hours, and press the Calculate button:
The energy E in kilowatt-hours (kWh) is equal to the power P in watts (W), times the time period t in hours (hr) divided by 1000:
E(kWh) = P(W) × t(hr) / 1000