If you /did/ need to do it without `du` then it would be something like:
`dir <folder> -Recurse | measure -Property Length -Sum`
which is easier to remember than whatever the equivalent bash would be, imo.
Maybe not in a technical sense, but I've never encountered Bash without GNU coreutils (or busybox). I'm just comparing how I would solve a problem in a typical *nix environment, compared to a Windows environment.
If you /did/ need to do it without `du` then it would be something like:
`dir <folder> -Recurse | measure -Property Length -Sum`
which is easier to remember than whatever the equivalent bash would be, imo.