Octal to Decimal Converter
Enter an octal (base-8) number to convert it to decimal (base-10).
Enter an octal number above
Formula
Multiply each digit by 8ⁿ (where n is position from right starting at 0) and sum the results.
How to Convert Octal to Decimal
Multiply each octal digit by its place value (powers of 8) and add the results together.
Example: Convert 377 (octal) to decimal
3×8² + 7×8¹ + 7×8⁰ = 192 + 56 + 7 = 255
3×8² + 7×8¹ + 7×8⁰ = 192 + 56 + 7 = 255
Conversion Table
| Octal | Decimal |
|---|---|
| 7 | 7 |
| 10 | 8 |
| 17 | 15 |
| 77 | 63 |
| 100 | 64 |
| 377 | 255 |
| 777 | 511 |
| 1000 | 512 |
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Last updated: 2025