Electrical energy cost calculator and how to calculate.
The energy E in kilowatt-hours (kWh) per day is equal to the power P in watts (W) times number of usage hours per day t divided by 1000 watts per kilowatt:
E(kWh/day) = P(W) × t(h/day) / 1000(W/kW)
The energy cost per day in dollars is equal to the energy consumption E in kWh per day times the energy cost of 1 kWh in cents/kWh divided by 100 cents per dollar:
Cost($/day) = E(kWh/day) × Cost(cent/kWh) / 100(cent/$)