CHMOD Calculator

What do file permissions mean?

Unix files have three permission types — read (r), write (w) and execute (x) — for three groups: the owner, the group and everyone else. Each combination creates a three-digit mode.

How is the number calculated?

Each set of rwx permissions is a value from 0 to 7. Read is worth 4, write 2 and execute 1. For example read and write gives 6, and all three gives 7.

What do common modes mean?

• chmod 755 — owner can read, write and execute; others can read and execute.
• chmod 644 — owner can read and write; others can only read.
• chmod 600 — only the owner can read and write.

What is the symbolic form?

Alongside the number, the symbolic notation like rwxr-xr-x describes the same permissions as ten characters: one for the type and nine for the three groups.

How do I use the calculator?

Tick the boxes for each permission and group, or press a preset button like 755 or 644. The numeric value updates live and can be copied in one click.

How to use CHMOD Calculator

Tick the permission boxes to build a mode. The octal value and rwx notation update live, and preset buttons apply common modes.

Use the controls above to provide your input or choose options, then review the result on the page.

Why use our CHMOD Calculator

• Build Unix file permissions visually and copy the numeric or symbolic mode.
• Complete the task with a focused CHMOD Calculator workflow instead of switching between apps.
• Open it in your browser and get started—no account or installation required.