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Octal to Decimal Converter
Enter a octal number to convert it to decimal immediately. Paste multiple values (one per line) for bulk conversion. Arbitrary-precision math means even 128-bit values convert exactly.
Octal to Decimal Converter
How to convert octal to decimal
Octal (base 8) uses digits 0–7; each octal digit maps to exactly three bits, which is why Unix file permissions (e.g. 755) are written in octal. Decimal (base 10) is the everyday number system, using digits 0–9.
Worked example converting 326:
- Expand by place value:
3×82 + 2×81 + 6×80= 214 in decimal. - Result:
326(octal) =214(decimal).
Accepted input formats
- Optional prefixes:
0b(binary),0o(octal),0x(hex). - Spaces, commas and underscores are ignored, so
1101_0110works. - A leading minus sign converts negative values (sign-magnitude, not two's complement).
- Hexadecimal is case-insensitive; output is upper-case.
Octal to Decimal reference table
| Octal | Decimal |
|---|---|
| 0 | 0 |
| 1 | 1 |
| 2 | 2 |
| 3 | 3 |
| 4 | 4 |
| 5 | 5 |
| 6 | 6 |
| 7 | 7 |
| 10 | 8 |
| 11 | 9 |
| 12 | 10 |
| 13 | 11 |
| 14 | 12 |
| 15 | 13 |
| 16 | 14 |
| 17 | 15 |
| 20 | 16 |
| 40 | 32 |
| 100 | 64 |
| 144 | 100 |
| 200 | 128 |
| 377 | 255 |
| 400 | 256 |
| 2000 | 1024 |
| 10000 | 4096 |
| 177777 | 65535 |
Frequently asked questions
What is 326 in decimal?
326 in octal equals 214 in decimal.
Is there a size limit?
No practical limit. The converter uses JavaScript BigInt, so values with hundreds of digits convert exactly without rounding.
Is my data sent to a server?
No. The conversion runs entirely in your browser; nothing you type is uploaded.