chmod Calculator (Octal ↔ rwx)
Convert Linux permissions between octal and symbolic notation with visual checkboxes. 100% in your browser.
| Read | Write | Execute | |
|---|---|---|---|
| Owner | |||
| Group | |||
| Other |
Each octal digit sums: read = 4, write = 2, execute = 1. For example, 644 = owner reads and writes, group and others only read — the typical permission for a file. 755 = owner has everything, everyone else only reads and executes — typical for a folder or script.
Built by
Miguel Ángel Colorado Marin (MACM)
Built by
Miguel Ángel Colorado Marin (MACM)
Full-Stack Developer · Guadalajara, España
I develop web apps, digital tools and full projects — from design to deployment.
This calculator converts Linux/Unix file and folder permissions between octal notation (like 755 or 644) and symbolic notation (like rwxr-xr-x), in both directions. Check the read, write and execute boxes for owner, group and other, and watch the octal number and symbolic text update instantly — or type the octal number directly and the boxes check themselves. Each octal digit is the sum of read (4), write (2) and execute (1) for that user group. The full chmod command is ready to copy and paste into your terminal.
Features
- ✓Visual checkboxes for owner, group and other
- ✓Bidirectional octal ↔ symbolic conversion
- ✓Ready-to-copy chmod command
- ✓Explanation of how each digit is calculated
- ✓100% in browser, no uploads
How to use the chmod calculator?
- 1
Check the permissions
Read, write and execute for owner, group and other.
- 2
Or type the octal directly
Type for example 755 and the boxes check themselves.
- 3
Copy the command
The full chmod command is ready to paste into your terminal.
Frequently asked questions
What does each octal digit mean?
It's the sum of read (4), write (2) and execute (1). For example, 6 = 4+2 = read and write without execute; 7 = 4+2+1 = all three permissions.
What exactly are 755 and 644?
755 (rwxr-xr-x) is typical for folders and executable scripts: the owner has full control, everyone else can only read and execute. 644 (rw-r--r--) is typical for normal files: the owner reads and writes, everyone else only reads.
Is anything uploaded to a server?
No, it's a purely mathematical calculation that happens in your browser.
Related tools
Embed chmod Calculator on your site
Add chmod Calculator to any web page with a simple iframe. Free, with attribution to miguelacm.es.
<iframe
src="https://miguelacm.es/embed/chmod-calculator"
width="100%"
height="700"
frameborder="0"
title="chmod Calculator — miguelacm.es"
></iframe>