Enter the normal force and the friction force into the calculator to determine the contact force.

Contact Force Formula

The following equation is used to calculate the Contact Force.

Fc = SQRT (N^2 + F^2)
  • Where Fc is the contact force (N)
  • N is the normal force (N)
  • F is the friction force (N)

To calculate the contact force, sum the squares of the normal force and friction force, then take the square root of the result.

What is a Contact Force?


A contact force is a measure of the net force acting on an object that is in contact with another object. Typically this refers to the contact between an object and an incline plane.

How to Calculate Contact Force?

Example Problem:

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

First, determine the normal force. In this example, the normal for is equal to the mass time the acceleration due to gravity and is calculated to be 500 N.

Next, determine the force due to friction. In this case, the friction force is calculated to be 200 N.

Finally, calculate the total contact force using the formula above:

Fc = SQRT (N^2 + F^2)

Fc = SQRT (500^2 + 200^2)

Fc = 538.51 N