Trusses are mechanical structures made from a number of triangular units. The triangle is a structurally stable shape, so when a force acts on a truss, the load is applied only at the truss joints. This makes the truss one of the easier architectural components to analyse in theory but, in practice, joints may not remain entirely rigid, and loads may apply along each entire bar or beam rather than simply on the joints. The easiest way to calculate a truss force is to input your data into an appropriate computer program or online resource.

Launch your web browser and go to the Cornell truss force calculator site (see link in the Resources section).

Select the type of truss you're calculating from the "Truss type" drop-down box.

Enter the truss dimensions in the "Overall length" and "Height" text input boxes.

Enter the hinge and roller node number in the applicable fields.

Enter the vertical and horizontal loads on each node in their relevant text boxes.

Select the nodes whose force you want to calculate from the "Select bar between" drop-down boxes.

Click "Update." The displayed figure is the truss force.