Enter the number of defects found internally and the number of defects found externally into the Defect Removal Efficiency Calculator. The calculator will evaluate the Defect Removal Efficiency. 

Defect Removal Efficiency Formula

The following two example problems outline the steps and information needed to calculate the Defect Removal Efficiency.

DRE = DI / (DI + DE) * 100

Variables:

  • DRE is the Defect Removal Efficiency (%)
  • DI is the number of defects found internally 
  • DE is the number of defects found externally 

To calculate the defect removal efficiency, divide the number of internal defects by the sum of the internal and externally found defects, then multiply by 100.

How to Calculate Defect Removal Efficiency?

The following steps outline how to calculate the Defect Removal Efficiency.


  1. First, determine the number of defects found internally. 
  2. Next, determine the number of defects found externally. 
  3. Next, gather the formula from above = DRE = DI / (DI + DE) * 100.
  4. Finally, calculate the Defect Removal Efficiency.
  5. After inserting the variables and calculating the result, check your answer with the calculator above.

Example Problem : 

Use the following variables as an example problem to test your knowledge.

number of defects found internally = 300

number of defects found externally = 80

DRE = DI / (DI + DE) * 100 = ?