About Unix Permissions Calculator
Calculate Unix/Linux file permissions visually. Convert between numeric (755) and symbolic (rwxr-xr-x) notation. Common presets included.
Frequently Asked Questions
What do the numbers mean in chmod 755?
Each digit represents permissions for owner, group, and others. 7=rwx (read+write+execute), 5=r-x (read+execute), 4=r-- (read only). Sum of r(4)+w(2)+x(1).
What is the difference between 755 and 644?
755 is typically for directories and executables (owner can rwx, others can rx). 644 is for regular files (owner can rw, others can r only).
What does chmod +x do?
chmod +x adds execute permission for all users. It is commonly used to make scripts executable. Equivalent to adding x to the current permissions.