The MacBook Neo starts at $599 with 256 GB. The base MacBook Air has the same.

That’s plenty on day one. macOS takes about 25 GB, and you look at the 200-something GB left and think you’ll never fill it.

(I wrote this with help from an AI assistant. Every number is measured on my own Mac.)

I thought that too. My MacBook Air has a 245 GB disk. Today it has 4.13 GB free , and the biggest thing on it is not my photos or my projects. It’s a grey bar called “System Data” at 142.69 GB .

This post is the setup I’d do on a new 256 GB Mac, knowing what I know now. Most of it is free and built into macOS.

What actually fills a small Mac

Not what you’d guess. I measured mine folder by folder:

App data, 39.31 GB. The private folders apps keep in ~/Library/Application Support : databases, offline content, downloaded models. It grows quietly, and it stays behind when you delete the app.

Shared Library and Homebrew, 31.88 GB. That one’s on me. I’m a developer.…