Live tool

chmod Permission Calculator

Convert chmod values between numeric and symbolic formats, inspect owner, group, and others permissions with a live interactive grid, compare two chmod values side-by-side, view an octal bit breakdown, and get risk indicators — plus a ready-to-use chmod command.

Input

Enter a numeric chmod value, a symbolic value, or both if they match.

3 digits (e.g. 755) or 4 digits with special bits (e.g. 4755).
9 characters — setuid/setgid show as s/S, sticky as t/T.
Used in the command preview for direct copy-paste.
Owner
Group
Others
Read (r)
Write (w)
Execute (x)
Reset

Result

Owner, group, others breakdown with ready-to-use command preview.

Numeric 444
Symbolic r--r--r--
Owner r--
Group r--
Others r--
Command preview chmod 444 demo-file.txt

What this means

Owner can read.

Group can read.

Others can read.

For demo-file.txt, the owner can read. Users in the group can read. Everyone else can read.

Common presets

Compare permissions

Type two chmod values to compare them side-by-side, bit by bit.

A
B
Diff type a value in A and B to compare

Recent history

Last 5 chmod values you used.

No history yet.

How chmod works

chmod maps numeric values to owner, group, and others permissions.

Numeric notation

Each digit represents permissions for owner, group, and others.

Permission values

4 = read, 2 = write, 1 = execute.

Practical example

755 becomes rwxr-xr-x.

Special bits

A leading digit adds setuid (4), setgid (2), or sticky (1) — e.g. 4755, 1777.

Related tool

Calculate permissions from a Linux umask value.

Need to calculate the resulting file and directory permissions from a Linux umask value?

Open umask Calculator