chmod Calculator Online
Calculate Unix file permissions visually. Get octal, symbolic, and chmod command.
| Read (r) | Write (w) | Execute (x) | Octal | |
|---|---|---|---|---|
| Owner | 6 | |||
| Group | 4 | |||
| Others | 4 |
644
rw-r--r--
chmod 644 filename
What Is a chmod Calculator?
A chmod calculator helps you set Unix/Linux file permissions visually without memorizing octal values. Toggle checkboxes for Read, Write, and Execute permissions for Owner, Group, and Others — and instantly see the octal notation (e.g. 755), symbolic notation (e.g. rwxr-xr-x), and the ready-to-run chmod command. You can also type an octal value directly to set the checkboxes.
How to Use chmod Calculator
- Click the checkboxes to toggle Read, Write, and Execute for each entity (Owner, Group, Others).
- Or type a 3-digit octal value (e.g. 755) in the input field to auto-set the checkboxes.
- Copy the Octal, Symbolic, or Command result with the Copy button.
Features
- Visual permission grid — toggle read/write/execute for owner, group, others
- Octal input — type a 3-digit octal to auto-populate checkboxes
- Three output formats — octal (755), symbolic (rwxr-xr-x), chmod command
- One-click copy — copy any result to clipboard
- Instant updates — all outputs update as you click
FAQ
What does chmod 755 mean?
chmod 755 means the owner has read, write, and execute (7), while group and others each have read and execute (5). In symbolic notation: rwxr-xr-x. This is a common permission for executable files and directories.
What is the difference between octal and symbolic notation?
Octal notation uses three digits (e.g. 755) where each digit represents the combined permission bits for owner, group, and others. Symbolic notation uses letters (e.g. rwxr-xr-x) where r=read, w=write, x=execute, and - means no permission.
How do I calculate chmod permissions?
Each permission type has a numeric value: read=4, write=2, execute=1. Add the values for each entity (owner, group, others) to get the octal digit. For example, read+write+execute = 4+2+1 = 7, read+execute = 4+1 = 5.
What is chmod 644?
chmod 644 gives the owner read and write (6), while group and others have read-only (4). In symbolic notation: rw-r--r--. This is the standard permission for regular files.