When we moved to Colorado Springs I made a garage gym. One of the pieces that got dropped from the list to save money was plyometric boxes. Well I am eager to add them and my obsessive compulsive disorder tendencies show it.

I found plans in a CrossFit Journal article from September 2006 that describes how to make Plyo Box with Slanted Sides. The article was excellently written and provided the dimensions for a 20” box.

My searching also found a fun video titled Plyometric Box - How to Build. I love the simplicity of the video - simple, but a nice quality to it. The creator of the video talked about scaling the CrossFit plans for different size boxes, but didn’t provide details. That got my engineering mind wandering.

Scaling dimensions Why not build an excel spreadsheet that lets me set the height of the box and have it calculate the dimensions of the side panels?

Why not indeed!

The spreadsheet defaults to the plans in the Crossfit Journal to build a 20” box with a top that is 17” square and sides angled at 9.5 degrees. The journal article says they used 10 degrees, but I found the dimensions matched more closely when I changed the angle slightly. Just for reference here are a few key dimensions for the boxes I would like to make.

Box HeightSide HeightBase Width
2018.523.6
1210.420.9
1816.522.9
2422.625

Note: Some people have suggested that you don’t need to add two layers of plywood for the top. These dimensions assume two layers, plus a 1/4” thick rubber mat.