The page provides you the energy consumption formulas to calculate the electricity consumption and electricity cost for a day, month and year. The formula used here for energy consumption is (p x h) / 1000, where 'P' is power consumption and 'h' stands for hours of use per day. In terms of finding the usage for month or year, multiply 30 and 365 respectively to the resulting value. For finding the electrical cost, apply the same formula and multiply electricity cost per Unit with the result.