How to add to the name of a folder the total size of the files it contains

I would like to know if it is possible to add to the name of a folder the total size of the files it contains, regardless of their extension.

For example, I have a folder X with 3 files, the first is 1.5 GB, the second is 3.2 GB, and the third is 0.5 GB, and I would like to rename the folder to X 5.2 GB, which is the sum of the size of the 3 files it contains.

Thank you very much for your attention and I apologize for my bad English.