Octal Numeral Converter
Decimal → Octal
Octal → Decimal
Octal Value (Base-8):
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About Octal (Base-8)
The octal system uses 8 as its base, with digits ranging from 0 to 7. It was historically popular in computing because it easily converts to binary.
Each octal digit corresponds to exactly three binary digits (bits), making it a compact way to represent binary data. For example, octal 755 is binary 111 101 101.
Octal Calculator
Result:
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Unix File Permissions Calculator
Click the checkboxes to set Read (4), Write (2), and Execute (1) permissions for each user class. The octal code will update automatically.
Octal Reference
Octal to Binary Conversion
Each octal digit maps directly to a 3-bit binary number. This makes conversion between the two systems very fast.
| Octal | Decimal | Binary (3-bit) |
|---|---|---|
| 0 | 0 | 000 |
| 1 | 1 | 001 |
| 2 | 2 | 010 |
| 3 | 3 | 011 |
| 4 | 4 | 100 |
| 5 | 5 | 101 |
| 6 | 6 | 110 |
| 7 | 7 | 111 |