Kitsy AI

🔢Chmod Calculator

Calculate Unix file permissions (octal & symbolic)

PermissionOwnerGroupOthers
Read
Write
Execute

Want a deeper walkthrough? Read our complete guide to Chmod Calculator →

About the Chmod Calculator

Chmod Calculator converts Unix file permissions between the checkbox view, the symbolic form (like rwxr-xr-x), and the octal form (like 755) used by the chmod command. Toggle read, write, and execute for owner, group, and others — or type an octal value to decode it.

It is a fast reference for getting permissions right without memorizing the bit math.

Common use cases

  • Working out the octal value for a chmod command
  • Decoding what 644 or 755 actually means
  • Setting correct permissions for scripts and SSH keys
  • Learning how Unix permission bits map to numbers

How to use the Chmod Calculator

  1. Tick the read, write, and execute boxes for owner, group, and others.
  2. Read the octal and symbolic values, or type an octal number to set the boxes.
  3. Copy the ready-to-run chmod command.

Frequently asked questions

What does chmod 755 mean?

Owner can read, write, and execute (7); group and others can read and execute (5). It is common for directories and executable scripts.

What is the difference between 644 and 755?

644 grants no execute permission (typical for regular files); 755 adds execute for everyone (typical for scripts and folders).

How is the octal calculated?

Read=4, write=2, execute=1. Add them per group: rwx = 7, rw- = 6, r-x = 5, and so on.