chmod (change mode) is a Unix/Linux command that sets file permissions. Permissions control who can read, write, or execute a file.

What do the numbers mean?

Each digit represents permissions for Owner, Group, and Others. Read=4, Write=2, Execute=1. For example, 755 means rwx for owner, r-x for group, and r-x for others.

What is symbolic notation?

Symbolic notation uses letters: r (read), w (write), x (execute), and - (no permission). For example, rwxr-xr-x is the symbolic form of 755.

Is my data sent to a server?

No. All calculation happens entirely in your browser. Nothing is transmitted to any server.

Chmod Calculator

Visual file permission calculator with octal and symbolic output.

How to Use Chmod Calculator

Step 1

Toggle Read, Write, and Execute checkboxes for Owner, Group, and Others.

Step 2

See the octal code (e.g. 755) update live.

Step 3

See the symbolic representation (e.g. rwxr-xr-x) update live.

Step 4

Or type an octal code to set the checkboxes automatically.

Features

Visual grid with checkboxes for Owner, Group, and Others.

Live octal and symbolic representation.

Input field to type octal and update checkboxes.

Copy buttons for both octal and symbolic values.

Completely client-side — no data leaves your browser.

FAQ

: chmod (change mode) is a Unix/Linux command that sets file permissions. Permissions control who can read, write, or execute a file.
: Each digit represents permissions for Owner, Group, and Others. Read=4, Write=2, Execute=1. For example, 755 means rwx for owner, r-x for group, and r-x for others.
: Symbolic notation uses letters: r (read), w (write), x (execute), and - (no permission). For example, rwxr-xr-x is the symbolic form of 755.
: No. All calculation happens entirely in your browser. Nothing is transmitted to any server.

Role	Read	Write	Execute	Octal
owner				7
group				5
others				5