chmod Calculator
Octal ↔ symbolic permissions
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chmod Calculator
Octal ↔ symbolic permissions
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About this tool
Toggle read/write/execute bits per user, group and other, and see the numeric and symbolic equivalents.
The chmod Calculator converts between the two ways Unix file permissions are written: the symbolic triplet rwxr-xr-x and the three-digit octal value 755. Toggle read, write and execute for the owner, group and others, and the octal number, the symbolic string and the chmod mode expression update as you go.
The third output is the mode expression chmod itself accepts — u=rwx,g=rx,o=rx — ready to place in a command such as chmod u=rwx,g=rx,o=rx file. A category with nothing ticked is written u=- rather than left blank, so the expression stays valid. Preset chips cover 400, 600, 644, 664, 700, 755 and 777, and the octal box also accepts a value you type.
This is a permissions calculator for the nine permission bits only: it does not set setuid, setgid or the sticky bit, and it cannot read or change any file. Everything runs in the tab — no file path or permission data leaves your machine.
Key features
Everything you get with chmod Calculator — no premium upsell.
Toggle read, write and execute for owner, group and others
Live octal (755), symbolic (rwxr-xr-x) and chmod-style (u=rwx,g=rx,o=rx) output
Type a three-digit octal value or pick a preset from 400 to 777
A category with no bits set is written u=- so the mode stays valid
Copy any of the three representations
Client-side only — no permission data transmitted anywhere
How to use chmod Calculator
Follow the steps below to use the tool.
- 1
Toggle permissions
Tick or untick read (4), write (2) and execute (1) for owner, group and others. The three outputs update immediately.
- 2
Read the octal and symbolic forms
The numeric value (755) and the symbolic string (rwxr-xr-x) are the same permissions written in the two notations.
- 3
Or type an octal mode
Type a three-digit value such as 644 into the octal box and the checkboxes follow. Digits 8 and 9 are refused because this is octal, and a value applies only once all three digits are entered.
- 4
Copy the chmod mode
Copy the chmod-style expression (u=rwx,g=rx,o=rx) and use it as the mode argument to chmod.
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Launch chmod CalculatorFrequently asked questions
Quick answers before you launch the tool.
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