Enter the wasted units, total time spent, overall productivity, and efficiency into the calculator to determine the Inefficiency Index.

Inefficiency Index Formula

The following formula is used to calculate the Inefficiency Index.

II = (WU * T) / (OP * E)


  • II is the Inefficiency Index
  • WU is the wasted units (units)
  • T is the total time spent (hours)
  • OP is the overall productivity (units/hour)
  • E is the efficiency (decimal)

To calculate the Inefficiency Index, multiply the wasted units by the total time spent. Then divide this result by the product of the overall productivity and the efficiency. The higher the Inefficiency Index, the more inefficient the process is.

What is an Inefficiency Index?

An Inefficiency Index is a statistical measure used to determine the level of inefficiency in a particular system or process. It quantifies the amount of wasted resources, such as time, money, or energy, in relation to the total resources used. A higher index indicates a higher level of inefficiency, suggesting that there is significant room for improvement in the system or process being evaluated. This index can be used in various fields, including economics, business, and engineering, to identify areas that need optimization and to track the progress of efficiency-enhancing initiatives.

How to Calculate Inefficiency Index?

The following steps outline how to calculate the Inefficiency Index.

  1. First, determine the wasted units (WU) in units.
  2. Next, determine the total time spent (T) in hours.
  3. Next, determine the overall productivity (OP) in units per hour.
  4. Finally, determine the efficiency (E) as a decimal.
  5. After gathering all the variables, use the formula II = (WU * T) / (OP * E) to calculate the Inefficiency Index.

Example Problem:

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

wasted units (WU) = 10 units

total time spent (T) = 5 hours

overall productivity (OP) = 8 units/hour

efficiency (E) = 0.9