Enter the applied pressure (psi) and the applied area (in^2) into the Calculator. The calculator will evaluate the Extension Force. 

Extension Force Formula

EF = AP * A


  • EF is the Extension Force (lbf)
  • AP is the applied pressure (psi)
  • A is the applied area (in^2)

To calculate Extension Force, multiply the applied pressure by the applied area.

How to Calculate Extension Force?

The following steps outline how to calculate the Extension Force.

  1. First, determine the applied pressure (psi). 
  2. Next, determine the applied area (in^2). 
  3. Next, gather the formula from above = EF = AP * A.
  4. Finally, calculate the Extension Force.
  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.

applied pressure (psi) = 40

applied area (in^2) = 20


What is applied pressure?

Applied pressure refers to the force per unit area exerted on a surface in a direction perpendicular to that surface. It is measured in pounds per square inch (psi) in the context of calculating extension force.

How do I measure the applied area?

The applied area is the surface area over which the force is applied, measured in square inches (in^2). It can be measured by calculating the length times the width of the surface for rectangular shapes, or by using appropriate formulas for other shapes.

Can extension force be negative?

Typically, extension force is considered to be a positive value, representing a force that extends or stretches an object. However, if the applied pressure is negative, indicating a pull or suction force, the calculated extension force might be conceptualized as negative in specific contexts.

What applications might require the calculation of extension force?

Calculating extension force is crucial in engineering, design, and physics. It is used in designing mechanical systems like springs, hydraulic and pneumatic systems, and in understanding the structural integrity of materials under pressure.