Enter the billet area, extruded product area, and the extrusion constant into the calculator to determine the extrusion force.

Extrusion Force Formula

The following equation is used to calculate the Extrusion Force.

EF = A0 * k * ln ( A0/Af)
  • Where EF is the extrusion force (lbf)
  • A0 is the billet area (in^2)
  • Af is the extruded product area (in^2)
  • k is the extrusion constant (lbf/in^2)

To calculate the extrusion force, multiply the billet area by the extrusion constant, then multiply by the natural log of the ratio of the billet area to the extruded product area.

What is an Extrusion Force?


An Extrusion Force measures the amount of force it takes to extrude (or push) plastic into a die. The force is measured in pounds or Newtons. The higher the force, the more difficult it is to extrude a part.

How to Calculate Extrusion Force?

Example Problem:

The following example outlines the steps and information needed to calculate the Extrusion Force.

First, determine the billet area. In this example, the billet area is measured to be 12 in^2.

Next, determine the extruded product area. The extruded product area in this problem is 8 in^2.

Next, determine the extrusion constant. This is calculated to be 50 lbf/in^2.

Finally, calculate the extrusion force using the formula above;

EF = A0 * k * ln ( A0/Af)

EF = 12 * 50 * ln ( 12/8)

EF = 243.27 lbf