To calculate the beam height, use the following rule of thumb:
Here’s an example:
With such a cross-section, the beam may protrude 1.0 m on each side.
It is not the total length of the beam that is important, but the distance between the supports (here 400 cm):
The calculated height h here is therefore 20 cm.
This value can be increased by 2 - 4 cm if you expect very large loads.
The value can be reduced by 2 cm if you only build a platform, without a treehouse, without large crowds.
The beam width b should always be > 6 cm so that you have enough space for screwing.