I needed to calculate the measurements for a christmas tree, so I've created a parametric model of it. 

The picture contains three wooden and a tiny print of the model with 19mm total height.

Ideas came from pages like https://www.charlestoncrafted.com/diy-2x4-wood-christmas-tree/ or this youtube video: 

The openscad model is parametric, thus you can change the width of the wood and the height of each step.