What does chmod 755 mean?

755 gives the owner full read, write, and execute permission, and gives the group and everyone else read and execute. It's a common setting for directories and executable scripts.

What is the difference between 644 and 755?

644 allows the owner to read and write while others can only read — typical for regular files. 755 adds execute permission, which is needed for directories and runnable scripts.

How do I convert symbolic permissions to octal?

Tick the read/write/execute boxes for each group above and the calculator shows the equivalent octal number you can pass to chmod.

All tools/Data Inspector

Chmod Calculator

Runs locally

Visually calculate Unix file permissions. Easily toggle read/write/execute and get the correct octal or symbolic syntax instantly.

Octal Value

Symbolic Value

-rwxr-xr-x

Quick Commands

Apply to file

chmod 755 file.txt

Apply recursively to directory

chmod -R 755 folder/

Using symbolic notation

chmod rwxr-xr-x file.txt

The chmod calculator converts Unix file permissions between the symbolic form (rwxr-xr-x) and the octal form (755) used by the chmod command. Tick the read, write, and execute boxes for owner, group, and others to get the exact number to run. Everything is computed in your browser.

How to calculate chmod permissions

1Tick read, write, and execute for owner, group, and others.
2Read the octal value (e.g. 755) and the symbolic string instantly.
3Copy the matching chmod command for your terminal.

How octal permissions work

Each permission group — owner, group, others — is a digit from 0 to 7, where read is 4, write is 2, and execute is 1. Add them up: 755 means the owner has read+write+execute (7) while group and others have read+execute (5). This calculator does the arithmetic for you in both directions.

Frequently asked questions

What does chmod 755 mean?: 755 gives the owner full read, write, and execute permission, and gives the group and everyone else read and execute. It's a common setting for directories and executable scripts.
What is the difference between 644 and 755?: 644 allows the owner to read and write while others can only read — typical for regular files. 755 adds execute permission, which is needed for directories and runnable scripts.
How do I convert symbolic permissions to octal?: Tick the read/write/execute boxes for each group above and the calculator shows the equivalent octal number you can pass to chmod.