How big is a Git commit?

A Git commit size is approximately 50 bytes when it contains only a commit message, 50-100 bytes with a single file, and up to 1.5 MB with multiple files. The size is determined by the commit object's metadata and the size of the files being committed. The size of the commit object is the sum of the size of the commit message, the size of the commit tree, and the size of the tree's blobs (file objects). The commit tree itself is a binary object that contains the file names, modes, and SHA-1 hashes of the files being committed. The blobs are the actual file contents.