Energy Consumption Formula

How to Calculate Energy Consumption?

Energy consumption can be simply said to be the use of a specific amount of energy or power output. This can be the energy consumption related to the consumption of electrical power generated by power plants or the energy derived from food in the case of biological living organisms. Although both are energy consumption and both of them have their own unique formulas, here we are primarily going to discuss the energy consumption regarding the consumption of an electrical output or the energy generated by a power plant. 

As mentioned, energy consumption is the use of the power of the energy of any system by making use of the supplied power. Energy is measured in terms of Joules as it is the standard unit of energy measurement, and so the energy consumption is typically observed in Gigajoules per year which is kilograms of the oil equivalent per year and in Watts. Hence, the energy calculation formula or the formula of energy consumed for determining energy consumption is obtained by calculating the number of power units consumed over a given time period. 

Energy Consumption Formula

As mentioned above in the introduction, energy consumption is measured by multiplying the number of power units consumed within the time period over which it has been consumed. Hence, the energy consumption formula or the power consumption formula is given as below:

E = P*(t/1000); where E = energy measured in Joules or in kilowatt-hours (kWh), P = power units in watts,  and t = time over which the power or energy was consumed.   

Thus, whenever someone asks you how to calculate power consumption, you can calculate and give the answer using the above equation. 

Energy consumption can be widely classified based on several factors such as worldwide energy consumption, its impact on the environment, etc. 

Based on the idea of demographic usage, energy consumption can be divided into the following categories:

  • Worldwide Energy Supply: The worldwide energy supply is a vast area that is defined based on the factors such as the global production and preparation of the fuel, generation of the electricity using that fuel, the transport of energy and energy consumption. 

  • Worldwide Energy Consumption: It is the overall energy consumed of the total available output of the energy produced which is huge in number. This is done by using the power consumption formula and calculating the total power consumption at different levels of demographics. 

  • Domestic Energy Consumption: Domestic energy consumption is defined as the total amount of energy consumed by a given household or for household work. Usually, the power consumption of a household activity calculated using the above-given power consumption formula may be small but when multiplied by the number of households of the population in a given demographic the number becomes significant. 

  • Electric Energy Consumption: This classification is defined based specifically on the consumption of electrical energy consumed. It does not include the amount of mechanical energy that is used to perform work. Here, the energy consumed formula or power consumed formula can be applied by taking the values of power units based on the meter readings installed at various places such as household or industrial locations. 

Energy consumption has been central to the development of human civilizations. White’s Law named after Leslie white and published in 1943 states that with most of the other factors remaining constant, “culture evolves as the amount of energy harnessed per capacity per year is increased or as the efficiency of the instrumental means of putting the energy to work is released”.

There are widespread effects of energy consumption worldwide. The impact of the energy industry on the environment has been huge and mostly negative. The ever-increasing amounts of energy being produced and the increasing rate at which the energy is consumed has resulted in the generation of harmful factors that have immensely contributed to the rise of Earth’s temperature significantly within a few years. Because of coal and petroleum products being used more and more until recently to produce and fulfil the immense needs of energy, there has been a continuous release of greenhouse gases such as carbon dioxide and different oxides of nitrogen that have contributed significantly to the greenhouse effect. Not only the production but the consumption of energy ranging from household activities to industrial activities have generated and released immense amounts of heat energy into the atmosphere. Therefore, unchecked production from non-renewable sources and the unchecked consumption of energy has resulted in global warming which needs to be taken seriously and taken care of. 


In order to curb and control the harmful effects of energy consumption, energy conservation is necessary. Energy conservation is the practice of decreasing the total quantity of energy or using the energy more efficiently and avoiding any wastage of energy. This not only addresses the challenge of wastage of energy resulting in equitable distribution of energy amongst the people but also in providing a cap on the energy requirements and the energy generated by the industries so that there is less release of greenhouse gases into the atmosphere thus, in turn, helping the environment and the planet from not going to the verge of drastic environmental changes and extinction of most of the species. 

FAQs (Frequently Asked Questions)

1. How to Calculate Power Consumption or How to Calculate Energy Consumption?

Ans: Energy calculation is very simple. Energy is calculated either in terms of Joules or in terms of kilowatt-hour (kWh). It is typically calculated by the number of power units used by the number of hours over which the power is consumed. 

2. What Causes Energy Consumption?

Ans: With the rising economic development, rising population and the technological developments the people are moving towards more and more comfortable lifestyles, with bare necessities growing beyond just a house, food and clothing. All these factors have resulted in increased energy consumption because as per White’s Law, culture evolves as the amount of energy consumed increases. 

3. Why is Energy Consumption So Important?

Ans: Energy plays a significant role in the lives of human beings and in the activities that drive the economy, thus becoming a scale of economic and social development and a basic humanitarian need. Hence, energy consumption per capita of a country is regarded as an important indicator for economic development and thus energy consumption becomes important.