Free Chmod Permissions Calculator
Work out Linux file permissions without guessing. Tick read, write, and execute for the owner, group, and others, and this calculator produces the matching octal number (like 755) and symbolic notation (like rwxr-xr-x) instantly.
How to Use
Use the checkboxes to grant or revoke read, write, and execute permissions for each of the three classes — Owner, Group, and Others. The octal value, symbolic string, and the ready-to-run chmod command update live.
- Octal output (e.g. 644, 755, 777)
- Symbolic output (e.g. rw-r--r--)
- Complete chmod command ready to copy
- Reverse lookup from an octal or symbolic value
Reading chmod permissions
Each permission class has three bits: read (4), write (2), and execute (1). Adding the granted bits gives a digit from 0 to 7, and the three digits together form the octal mode. For example, owner read+write+execute (4+2+1=7), group read+execute (4+1=5), and others read+execute (4+1=5) combine to 755. Common values are 644 for files and 755 for directories and scripts.
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