FILES/DIRECTORIES UNDER NTFS

How many files can a directory contain under NTFS? I know it depends on several factors; the cluster size, the number of directories/levels of directories already present, the size allocated to the MFT, etc., and I know NTFS uses 64-bit encoding (so theoretically it can have 16-exabyte files or 16 exabytes. Is there a formula or something that can give a realistic calculation based on these factors or a maximum size the MFT can grow to?