Enter the actual output force (N), the effort force (N), and the mechanical advantage into the calculator to determine the Lever Efficiency. 

Lever Efficiency Formula

The following formula is used to calculate the Lever Efficiency.

Elever = OF / (EF * MA) * 100
  • Where Elever is the Lever Efficiency (%)
  • OF is the actual output force (N) 
  • EF is the effort force (N) 
  • MA is the mechanical advantage 

To calculate the lever efficiency, divide the output force by the product of the effort force and the mechanical advantage, then multiply by 100.

How to Calculate Lever Efficiency?

The following example problems outline how to calculate the Lever Efficiency.

Example Problem #1

  1. First, determine the actual output force (N). In this example, the actual output force (N) is given as 50 .
  2. Next, determine the effort force (N). For this problem, the effort force (N) is given as  25 .
  3. Next, determine the mechanical advantage. In this case, the mechanical advantage is found to be 3.5.
  4. Finally, calculate the Lever Efficiency using the formula above: 

Elever = OF / (EF * MA) * 100

Inserting the values from above and solving yields: 

Elever = 50 / (25*3.5) * 100 = 57.14 (%)

Example Problem #2

Using the same method as above, determine the variables required by the equation. For this example problem, these are provided as:

actual output force (N) = 60

effort force (N) = 13

mechanical advantage = 5

Entering these given values yields: 

Elever = 60 / (13 * 5) * 100 = 92.307 (%)