Decimal to Octal Converter
Convert decimal numbers to octal instantly, with no size limit.
Converts live as you type, entirely in your browser using arbitrary-precision math — no size limit and nothing is sent anywhere.
Need the opposite? Octal to Decimal Converter
What is Decimal to Octal Converter?
Type a decimal number and get its octal (base 8) equivalent instantly, useful for working with Unix file permissions or legacy systems that use octal notation. The conversion runs live in your browser as you type, using arbitrary-precision math so very large decimal numbers still convert exactly rather than losing precision partway through.
Decimal to Octal Chart (0-15)
| Decimal | Octal |
|---|---|
| 0 | 0 |
| 1 | 1 |
| 2 | 2 |
| 3 | 3 |
| 4 | 4 |
| 5 | 5 |
| 6 | 6 |
| 7 | 7 |
| 8 | 10 |
| 9 | 11 |
| 10 | 12 |
| 11 | 13 |
| 12 | 14 |
| 13 | 15 |
| 14 | 16 |
| 15 | 17 |
How to Use the Decimal to Octal Converter
- 1
Enter a Decimal Number: Type any non-negative whole number, for example 493 or 64.
- 2
Read the Octal Result Instantly: The octal equivalent appears automatically as you type, with no button to click.
- 3
Copy the Result: Use the copy button to copy the octal value, for example to use directly with chmod.
How Decimal Converts to Octal
Octal is base 8, using only digits 0-7. The standard conversion method is repeated division by 8: divide by 8, keep the remainder as the next octal digit, divide the quotient by 8 again, and repeat until the quotient is 0. The octal result is the remainders read from last to first.
How to Convert Decimal to Octal
Converting 493: 493 ÷ 8 = 61 remainder 5, 61 ÷ 8 = 7 remainder 5, 7 ÷ 8 = 0 remainder 7. Reading the remainders in reverse order: 755, which is exactly the octal permission string behind the familiar chmod 755.
Examples
8 → 10
64 → 100
511 → 777 (the highest 3-digit octal value, all read/write/execute bits set)Frequently Asked Questions
Common questions about Decimal to Octal Converter.