If you look for dedicated separate tools that calculate directory sizes then those two (also Rust tools) can help:

1. `cargo install dirstat-rs` (binary is `ds`): Prints several lines showing the size of the directory and the top fattest children. Colored output.

2. `cargo install dua-cli` (binary is `dua`): Only prints one line with the specified directory size. Colored output.

Both are insanely fast (they use all CPU cores). Love them both.