Convert Decimal to Octal
Enter a Decimal number to get its Octal value — plus every other common base. Exact even for huge integers, all in your browser.
That's not a valid number for the selected base.
- Binary base 2
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- Octal base 8
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- Decimal base 10
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- Hexadecimal base 16
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Worked example
255 in Decimal converts to 377 in Octal. The converter above is pre-filled with this value — edit it to see the result update live.
Decimal to Octal reference table
| Decimal | Decimal | Octal |
|---|---|---|
| 10 | 10 | 12 |
| 16 | 16 | 20 |
| 32 | 32 | 40 |
| 100 | 100 | 144 |
| 255 | 255 | 377 |
Common uses
Commonly used to generate standard Unix file permission flags (like 644 or 755) from calculated numbers.
Related conversions
Need another base? The full number base converter handles any base from 2 to 36 and converts them all simultaneously.
Frequently asked questions
How do I convert Decimal to Octal?
Enter your Decimal value into the converter above and it shows the Octal equivalent — along with every other base — instantly. For example, 255 in Decimal becomes 377 in Octal.
Can it handle very large numbers?
Yes. The converter uses arbitrary-precision math, so even numbers with hundreds of digits convert exactly without the rounding errors you'd get from a normal calculator.
Is my data sent to a server?
No. Every conversion runs locally in your browser using standard JavaScript BigInt math, so nothing you enter is uploaded.