Chmod calculator
Work out Unix file permissions — toggle read/write/execute to get the octal (e.g. 755), symbolic and chmod command.
| Permission | Owner | Group | Others |
|---|---|---|---|
| Read | |||
| Write | |||
| Execute |
Read = 4, Write = 2, Execute = 1. Common: 644 (files), 755 (folders/scripts), 600 (private).
How to use
Tick the read, write and execute boxes for the owner, group and others, and the calculator shows the matching octal value (like 755), the symbolic notation (rwxr-xr-x) and the exact chmod command to run. You can also type an octal number and the checkboxes update to match.
It takes the guesswork out of Unix and Linux file permissions — no more remembering that read is 4, write is 2 and execute is 1. Copy the octal or the full chmod command with one click.
Everything is calculated in your browser; there's nothing to install and nothing is sent anywhere.
Examples
Set owner read/write/execute and others read/execute to get 755.
Give only the owner read and write for 600.
Owner read/write, group and others read gives the common 644.
Frequently asked questions
How do octal permissions work?
Each digit is the sum of read (4), write (2) and execute (1) for the owner, group and others. So 7 is rwx, 5 is r-x, 4 is r--.
What's the difference between 755 and 644?
755 (rwxr-xr-x) is typical for folders and scripts; 644 (rw-r--r--) is typical for regular files that shouldn't be executable.
Can I enter an octal value directly?
Yes. Type a three-digit octal number and the checkboxes and symbolic notation update automatically.
Does it cover special bits (setuid, sticky)?
It covers the standard three-digit owner/group/other permissions, which is what the vast majority of chmod use needs.
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