Chmod calculator

Decode Unix file permission bits.

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Updated 2026-09-20

Chmod calculator explained

Decode an octal Unix permission mode into owner, group and other read/write/execute bits. A fourth leading digit represents setuid, setgid and sticky bits, including uppercase S or T when execute is absent.

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A worked example

755 means rwxr-xr-x: the owner can read, write and execute, while group and others can read and execute. 1777 adds the sticky bit.

Before you use the result

This does not change a file. ACLs, ownership, mount options and operating-system rules also affect real access. No mode is automatically appropriate for every server.

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ToolOctopus. “Chmod calculator.” Updated 2026-09-20. https://tooloctopus.com/chmod-calculator.

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