chmod Permission Calculator
Convert Unix read, write and execute checkboxes into octal chmod permissions and symbolic notation. Inspect owner, group and others with a command template.
Change the settings or try a preset.
Calculates basic permissions only; no commands are executed. Special bits, ACLs, ownership and recursive changes are outside this tool. On directories, execute means traversal/search.
Using chmod Permission Calculator
Convert Unix read, write and execute checkboxes into octal chmod permissions and symbolic notation. Inspect owner, group and others with a command template.
- Choose a preset or adjust the controls.
- Click Calculate permissions and inspect the result.
- Read the status and limitations, then copy or download the output.
Example
644 Calculates basic permissions only; no commands are executed. Special bits, ACLs, ownership and recursive changes are outside this tool. On directories, execute means traversal/search.
Questions & answers
How are the numbers calculated?
Read is 4, write is 2 and execute is 1. Add each group of selected permissions separately: owner, group and others. For example, rw-r--r-- becomes 644.
Does 777 fix permission errors?
It grants read, write and execute to everyone, which is usually broader than needed. Choose permissions based on your application and operating system rather than using a universal preset.
What does execute mean for a directory?
It controls traversal or search through the directory. Read lists entries; write changes entries, subject to additional filesystem rules. File execution has different semantics.
Does this change files?
No. It produces a template command and a basic three-digit mode. It does not support setuid, setgid, sticky bits, ACLs or directory-specific special-bit preservation.
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