Web and Digital
CHMOD Calculator
CHMOD Calculator build Unix file permission octal and symbolic notation from owner, group, other, and special-bit selections.
Web and Digital
CHMOD Calculator
Build Unix file permission octal and symbolic notation from owner, group, other, and special-bit selections.
Formula
Each permission digit = read x 4 + write x 2 + execute x 1; special digit = setuid x 4 + setgid x 2 + sticky x 1.
About the CHMOD Calculator
Build Unix file permission octal and symbolic notation from owner, group, other, and special-bit selections.
How the CHMOD Calculator Works
The selected octal values are decoded independently into rwx triplets, with setuid, setgid, and sticky bits applied to execute positions in symbolic notation.
Formula
Each permission digit = read x 4 + write x 2 + execute x 1; special digit = setuid x 4 + setgid x 2 + sticky x 1.
The calculation runs in your browser. Values are validated for required ranges, compatible units, and method-specific restrictions before results are displayed.
Required Inputs
- Owner permissions (required).
- Group permissions (required).
- Other permissions (required).
- Special bits (required).
Results Reported
The result panel reports the final answer and the intermediate quantities needed to check the calculation:
- Octal mode
- Symbolic mode
- Decimal mode value
- Owner permissions
- Group permissions
- Other permissions
- Special permissions
CHMOD Calculator Example
Select Example Data in the calculator to load this reproducible input set:
| Input | Example value |
|---|---|
| Owner permissions | 7 |
| Group permissions | 5 |
| Other permissions | 5 |
| Special bits | 0 |
How to Use the Calculator
- Confirm that the calculator title and formula match the quantity you need.
- Enter every required value using the unit shown with its field.
- Select Example Data to inspect a valid input set, or enter your own values and select Calculate.
- Review all reported values and the displayed formula before using the answer.
- Use Copy Result or Download CSV when you need a reusable record.
Accuracy and Limitations
Permissions do not override filesystem mounts, ACLs, ownership, umask, capabilities, SELinux, or application policy. Review security impact before applying a mode.
Keep units consistent, use measurements that represent the actual situation, retain full precision during the calculation, and round only the final answer. Professional decisions may require current official rules, field measurements, laboratory methods, or specialist review.
Frequently Asked Questions
What does the CHMOD Calculator calculate?
Build Unix file permission octal and symbolic notation from owner, group, other, and special-bit selections.
Which formula does the CHMOD Calculator use?
Each permission digit = read x 4 + write x 2 + execute x 1; special digit = setuid x 4 + setgid x 2 + sticky x 1. The selected octal values are decoded independently into rwx triplets, with setuid, setgid, and sticky bits applied to execute positions in symbolic notation.
What should I check before using the CHMOD Calculator result?
Permissions do not override filesystem mounts, ACLs, ownership, umask, capabilities, SELinux, or application policy. Review security impact before applying a mode.