Created By : Naaz Fatima

Reviewed By : Phani Ponnapalli

Last Updated : May 19, 2023

Free Energy Efficiency Calculator tool is designed to find the proportions of energy in a short span of time. You have to enter input energy, output energy in the input fields of the calculator and press the calculate button to check the energy efficiency as output effortlessly.

Energy Input

Energy Output

How to Calculate Efficiency?

Below provided are the simple steps to find the energy efficiency of the appliances. Follow these principles and guidelines to obtain the output in less amount of time.

  • Find the input energy and output energy.
  • Divide the output energy by the input energy.
  • Multiply the obtained value by 100 to get the efficiency value.

Energy Efficiency Formula

Efficiency is defined as how close the outcome for the given input with as much as less possible wastage. Energy efficiency is the ratio of the amount of output energy generated to the input energy consumed. It is denoted by η.

The efficiency formula regarding energy is as follows:

η = (Energy output/Energy input) * 100%

The real-life applications are Return on investment and fuel efficiency.


Question: A heat engine takes 1530 J of energy as input and gives 450 J of heat energy as useful wok. Determine the efficiency of heat energy?


Given that

Energy output = 1530 J

Energy inout = 450 J

Efficiency = (Energy Output)/(Energy Input) * 100%

= 1530/450 * 100%

= 3.4 * 100%

= 340%

Therefore, efficiency of the heat engine is 340%.

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FAQ's on Energy Efficiency Calculator

1. How efficiency is calculated?

Efficiency is the ratio of output energy to input energy. Divide the output energy by input energy and multiply the result by 100 to check the result.

2. What is the unit of efficiency?

The efficiency has no unit because both numerator and denominator are having the same unit.

3. Write the differences between efficiency and effectiveness?

Effectiveness is the extent to which someone or something is successful in meeting the desired outcome. Efficiency is the performing activities with minimum time wastage & optimum resources usage. Performing a task in a correct way is efficient and performing a task accurately is the effectiveness.

4. What are examples of energy-efficient appliances?

The energy-efficient appliances are ceiling fans, air purifiers, heat pumps, dishwashers, refrigerators and so on.

5. What is the formula to calculate energy efficiency?

The formula to calculate the energy efficiency is (Output energy/input energy) * 100%.