Octal to Binary

What is the Octal to Binary Converter?

This tool converts octal numbers (base-8) to binary numbers (base-2). Each octal digit maps directly to exactly 3 binary bits.

Why Convert Octal to Binary?

Octal to binary conversion is useful when:

• Understanding Unix permissions — chmod values (755, 644) become clearer in binary
• Working with legacy systems — some older systems use octal notation
• Learning number systems — octal is a stepping stone between binary and decimal

The Conversion

Each octal digit converts to exactly 3 binary digits:

Example: 755 = 111 101 101 = 111101101

How to Use

1. Enter octal number — digits 0-7 only
2. View binary result — conversion is instant
3. Copy the result — use in your work

Unix Permission Example

• 7 → 111 (read + write + execute)
• 5 → 101 (read + execute)
• 4 → 100 (read only)

Tips

Each octal digit always produces exactly 3 binary bits, making the conversion straightforward and predictable.