That's likely the size of the entire checked out tree, which would include all of the files. I just ran the command here and my AOSP 11.0 checkout is 54GB, min

That's likely the size of the entire checked out tree, which would include all of the files. I just ran the command here and my AOSP 11.0 checkout is 54GB, minus any git history, since I clone from a local mirror and use '--reference' to avoid having to copy objects. A lot of the size here is from the various prebuilts, AOSP build is quite self-contained (jdk, clang, etc) and barely uses anything from the host.