chmod Calculator — Linux File Permission Converter
Enter three octal digits (0–7) for owner, group and others to get the symbolic notation and an explanation of exactly which read/write/execute permissions are active.
- 1
Owner bits
7 × 64 = 448Read=4, Write=2, Execute=1 → digit × 2⁶ (= bit position 6) - 2
Group bits
5 × 8 = 40Group digit × 2³ (= bit position 3) - 3
Decimalvärde
448 + 40 + 5 = 493
Hur fungerar denna kalkylator?
Each chmod octal digit encodes read (4), write (2) and execute (1) bits for owner, group and others. Add active bits: 7=rwx, 6=rw-, 5=r-x, 4=r--, 0=---. Three digits like 755 map to -rwxr-xr-x. Enter digits 0–7 for each group to see the full symbolic notation and per-group breakdown instantly.
Formel
How this is calculated
Linux and Unix file permissions are governed by three groups — owner (user), group and others — each holding three independent permission bits: read (r, value 4), write (w, value 2) and execute (x, value 1). Adding the values of the active bits produces a single octal digit 0–7 for each group. The three digits are concatenated to form the familiar chmod code, such as 755 or 644.
The nine-character symbolic notation is decoded from those three digits. Each group of three characters uses the same rule: if bit 2 is set the first character is "r", otherwise "-"; bit 1 gives "w" or "-"; bit 0 gives "x" or "-". Concatenating owner, group and others (prefixed with a file-type character, "-" for regular files) gives the full notation such as -rwxr-xr-x for 755.
Common presets: 755 (rwxr-xr-x) suits executables and directories — the owner can read, write and execute; everyone else can only read and execute. 644 (rw-r--r--) is the default for regular files — owner reads and writes, others read only. 600 (rw-------) is used for sensitive files like SSH private keys. Avoid 777 on production servers because it grants write access to every user on the system.
Vanliga frågor
chmod 755 decodes to rwxr-xr-x: the owner (digit 7 = r+w+x) can read, write and execute the file; group (digit 5 = r+x) and others (digit 5 = r+x) can only read and execute. This is the standard permission for public executables and shared directories.
For each three-character group, assign 4 for "r", 2 for "w", 1 for "x", and 0 for "-", then add them. rw- = 4+2+0 = 6; r-x = 4+0+1 = 5; rwx = 7; --- = 0. Join the three digits to get the octal code.
chmod 644 (rw-r--r--) gives the group read-only access. chmod 664 (rw-rw-r--) also grants the group write access. Use 664 when users in the same Unix group need to collaborate and edit the same files.
Även känt som
TG we-Calculate Editorial Team. (2026). chmod Calculator — Linux File Permission Converter [Online calculator]. TG we-Calculate. https://we-calculate.com/sv/calculator/chmod-calculator
TG we-Calculate Editorial Team. "chmod Calculator — Linux File Permission Converter." TG we-Calculate. 2026. https://we-calculate.com/sv/calculator/chmod-calculator.
TG we-Calculate Editorial Team, "chmod Calculator — Linux File Permission Converter," TG we-Calculate, 2026. [Online]. Available: https://we-calculate.com/sv/calculator/chmod-calculator
@misc{wecalculate_chmod_calculator, title = {chmod Calculator — Linux File Permission Converter}, author = {{TG we-Calculate Editorial Team}}, howpublished = {\url{https://we-calculate.com/sv/calculator/chmod-calculator}}, year = {2026}, note = {TG we-Calculate} }
Hjälpte denna kalkylator dig?