File permissions / chmod calculator
Enter octal, rwx, or a complete ugo specification, or select permissions by class, to see equivalent permission notations and an example chmod command. The setuid, setgid, and sticky special bits are also supported. Copy all 4 results together or save them as TXT. This screen does not change permissions on actual files.
What you can do
Enter permissions in four ways
Enter octal, rwx, or ugo notation, or select permissions for each class. Check other representations from the notation you know.
Check permissions including special bits
Supports permissions including setuid, setgid, and sticky bits. Normal read, write, and execute permissions are handled separately from special bits.
Get permission values and example commands
Displays octal, rwx, and ugo notation, plus a chmod example in which you replace the target path. You can copy all results or save them as text.
How to use
Specify input format and permissions
Choose the notation you know, such as octal, and enter the permission value. You can also select permissions for each class.
Calculate and check the notation
Press “Calculate” and check the same permissions in octal, rwx, and ugo notation, along with an example command.
Get the results you need
Copy the results or save them as text. When using an example command, replace path/to/file with the actual target path.
When to use it
Read numeric permission values
Convert values such as 755 or 644 in configuration documents to rwx notation to check the permissions for owner, group, and others.
Prepare chmod permission values
When you know the permissions needed, select them for each class to create the notation and example command. This page does not apply them.
Permissions for owner, group, and others
Consider the three classes separately
The owner is represented by u, the group by g, and others by o. Specify read, write, and execute or search permissions for each.
Represent permissions by adding 4, 2, and 1
Read r is 4, write w is 2, and execute/search x is 1. For example, 6 is 4+2 for read and write, and 5 is 4+1 for read and execute/search.
The first digit represents special bits
In 4-digit octal notation, the first digit represents setuid, setgid, and sticky. In rwx notation, s/t means the special bit is set with execute permission; S/T means it is set without execute permission. The effect varies by OS and target type.
Frequently asked questions
What is the difference between 755 and 644?
755 gives the owner read, write, and execute permissions, and the group and others read and execute permissions. 644 gives the owner read and write permissions, and the group and others read permission. Choose according to the use and target; neither is a universal recommendation.
Does this page also change actual file permissions?
No. This page only calculates representations of the permissions you enter and creates example commands. It does not read the current state of actual files either.
How many characters should I enter for rwx notation?
Enter 9 characters combining the permissions for owner, group, and others. Do not include the file-type character, such as “-” or “d”, at the beginning of output from ls and similar tools.
How should I enter ugo notation?
Specify all normal permissions for the 3 classes and the setting or clearing of special bits, as in u=rw,g=r,o=,u-s,g-s,o-t. This feature does not interpret expressions that change only some permissions or arbitrary chmod syntax.
Inputs and results
- Input
- 1–4 octal digits, 9-character rwx notation, a complete ugo specification, or permissions for each class.
- Results
- 4-digit octal, rwx, and ugo notation including special bits, and a chmod example.
- Get results
- Copy all four results together or save as TXT. Actual file permissions are not changed.