What's the difference between numeric and symbolic notation?

Numeric notation uses three digits (e.g., 755), where each digit represents permissions for owner, group, and others. Symbolic notation uses letters like rwxr-xr-x to represent the same permissions.

What does chmod 755 mean?

chmod 755 gives the owner full permissions (read, write, execute) and gives the group and others read and execute permissions only. It's the most common permission for web server files.

What are the most common chmod values?

644 (owner read/write, others read) for regular files, 755 (owner all, others read/execute) for directories and scripts, 600 (owner read/write only) for sensitive files like SSH keys.

What does the execute permission do on directories?

On directories, execute (x) permission means the ability to access and traverse the directory. Without it, users cannot cd into the directory or access any files within it, even if they have read permission.

What is the sticky bit?

The sticky bit (represented by 't' or numeric prefix 1) on a directory means only the file owner can delete or rename files within it. It's commonly used on /tmp directories. For example, chmod 1755 sets sticky on a directory.

How do I make a script executable?

Use chmod 755 for scripts that everyone should run, or chmod 700 for scripts only the owner should execute. The key is adding the execute (x) permission for the appropriate users.

Chmod Calculator

Calculate Unix file permissions in numeric and symbolic notation. Free, fast, and runs 100% in your browser.

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Chmod Calculator

Calculate Unix/Linux file permissions in numeric and symbolic notation.

Numeric (Octal)

755

Symbolic

-rwxr-xr-x

Commands

chmod 755 <file>

chmod u=rwx,g=rx,o=rx <file>

Common Permissions

About Chmod Calculator

The ZamDev Chmod Calculator helps you understand and set Unix/Linux file permissions by converting between numeric (octal) and symbolic (rwx) notation. Click checkboxes for read, write, and execute permissions for owner, group, and others — and see the numeric and symbolic equivalents update in real time. Essential for system administrators, DevOps engineers, and anyone deploying applications on Linux servers.

How It Works

1Toggle read (r), write (w), and execute (x) checkboxes for owner, group, and others.
2See the numeric (e.g., 755) and symbolic (e.g., rwxr-xr-x) notation update instantly.
3Or enter a numeric value to see the corresponding permission checkboxes.
4Copy the chmod command to use in your terminal.
5Reference common permission presets for quick selection.

Key Features

Lightning Fast

Processes instantly with zero server delays

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Your data never leaves your device

No Sign-up Required

Use this tool instantly — completely free

Works Everywhere

Compatible with all modern browsers and devices

Common Use Cases

Setting correct permissions for web server files (644) and directories (755)

Understanding permission requirements in deployment documentation

Debugging file access errors on Linux servers

Learning Unix file permissions for system administration

Configuring SSH key file permissions (600)

Setting executable permissions for shell scripts and binaries

Frequently Asked Questions

chmod calculatorfile permissions calculatorunix permissionslinux chmodpermission calculatorchmod 755chmod 644file permission toolrwx calculatorlinux file permissions

About Chmod Calculator

How It Works

1Toggle read (r), write (w), and execute (x) checkboxes for owner, group, and others.

2See the numeric (e.g., 755) and symbolic (e.g., rwxr-xr-x) notation update instantly.

3Or enter a numeric value to see the corresponding permission checkboxes.

4Copy the chmod command to use in your terminal.

5Reference common permission presets for quick selection.

Common Use Cases

Setting correct permissions for web server files (644) and directories (755)

Understanding permission requirements in deployment documentation

Debugging file access errors on Linux servers

Learning Unix file permissions for system administration

Configuring SSH key file permissions (600)

Setting executable permissions for shell scripts and binaries

Chmod Calculator

About Chmod Calculator

How It Works

Key Features

Common Use Cases

Frequently Asked Questions

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Let's build it together.

Chmod Calculator

About Chmod Calculator

How It Works

Key Features

Common Use Cases

Frequently Asked Questions

Need something custom?
Let's build it together.

Command Palette

Chmod Calculator

About Chmod Calculator

How It Works

Key Features

Common Use Cases

Frequently Asked Questions

Need something custom?Let's build it together.

Command Palette

Chmod Calculator

About Chmod Calculator

How It Works

Key Features

Common Use Cases

Frequently Asked Questions

Need something custom?Let's build it together.

Need something custom?
Let's build it together.

Need something custom?
Let's build it together.