Symbolic — octal permission grid.. Chmod Calculator is a free online tool from the ToolsRift Developer Tools collection. It runs entirely in your browser — nothing to install, no signup, and your data never leaves your device.
Toggle read, write and execute for owner, group and others, and the tool shows the matching octal (e.g. 755) and symbolic (rwxr-xr-x) representations to copy.
Owner has read, write and execute (7); group and others have read and execute (5). It is common for scripts and directories.
Each permission class sums read=4, write=2 and execute=1, so rw- is 6 and r-x is 5, giving three digits like 644 or 755.
644 grants execute to no one (typical for regular files); 755 adds execute for everyone, needed for scripts and directories.