Enter the total energy output (J) and the total energy input (J) into the Return on Energy Invested Calculator. The calculator will evaluate and display the Return on Energy Invested.

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## Return on Energy Invested Formula

The following formula is used to calculate the Return on Energy Invested.

**EROI = EO / EI * 100**

- Where EROI is the Return on Energy Invested (%)
- EO is the total energy output (J)
- EI is the total energy input (J)

## How to Calculate Return on Energy Invested?

The following example problems outline how to calculate Return on Energy Invested.

Example Problem #1:

- First, determine the total energy output (J).
- The total energy output (J) is given as: 175.

- Next, determine the total energy input (J).
- The total energy input (J) is provided as: 350.

- Finally, calculate the Return on Energy Invested using the equation above:

EROI = EO / EI * 100

The values given above are inserted into the equation below and the solution is calculated:

EROI = 175 / 350 * 100 = 50 (%)

Example Problem #2:** **

For this problem, the variables needed are provided below:

total energy output (J) = 600

total energy input (J) = 800

This example problem is a test of your knowledge on the subject. Use the calculator above to check your answer.

EROI = EO / EI * 100** = ?**