Decimal to Octal

What is the Decimal to Octal Converter?

This tool converts decimal numbers (base-10) to octal numbers (base-8), commonly used in Unix/Linux systems.

Why Convert Decimal to Octal?

Octal representation is useful for:

• Setting file permissions — converting permission values to chmod format
• Programming — octal literals in C, Python, JavaScript
• Understanding binary — octal groups 3 bits together
• Legacy compatibility — older systems and documentation

The Conversion

Divide by 8 repeatedly and collect remainders from bottom to top.

Example: 493 → 493÷8=61r5, 61÷8=7r5, 7÷8=0r7 → 755

How to Use

1. Enter decimal number — any positive integer
2. View octal result — uses digits 0-7 only
3. Apply the value — use with chmod or in code

Permission Calculation

For Unix permissions, each digit represents owner/group/others:

• 4 = read (r)
• 2 = write (w)
• 1 = execute (x)
• 7 = 4+2+1 = rwx (full access)

Example

To set rwxr-xr-x: owner=7, group=5, others=5 → chmod 755