Octal to Decimal Converter
Convert octal numbers into decimal numbers instantly. This Octal to Decimal Converter helps students, programmers, and developers convert base-8 numbers into base-10 values with accurate results.
Octal to Decimal Conversion Examples
| Octal | Calculation | Decimal |
|---|---|---|
| 10 | 1×8¹ + 0×8⁰ | 8 |
| 25 | 2×8¹ + 5×8⁰ | 21 |
| 100 | 1×8² + 0×8¹ + 0×8⁰ | 64 |
| 157 | 1×8² + 5×8¹ + 7×8⁰ | 111 |
| 777 | 7×8² + 7×8¹ + 7×8⁰ | 511 |
How Octal to Decimal Conversion Works
Octal numbers use base-8 numbering, where each digit can have a value from 0 to 7. Decimal numbers use base-10 numbering with digits from 0 to 9.
To convert octal to decimal, multiply each octal digit by the corresponding power of 8 and add all results together.
| Octal Number | Power | Value |
|---|---|---|
| 1 | 8² | 64 |
| 5 | 8¹ | 40 |
| 7 | 8⁰ | 7 |
Therefore: 157₈ = 111₁₀
Octal vs Decimal Number System
| Feature | Octal | Decimal |
|---|---|---|
| Base | 8 | 10 |
| Digits Used | 0 – 7 | 0 – 9 |
| Common Usage | Computing, permissions | Daily calculations |
| Example | 157 | 111 |
Common Uses of Octal Conversion
- Understanding computer number systems.
- Converting Unix/Linux file permissions.
- Learning programming and digital electronics.
- Working with low-level computer operations.
Frequently Asked Questions
An Octal to Decimal Converter changes base-8 numbers into base-10 decimal values automatically.
Multiply each octal digit by the power of 8 based on its position and add the results together.
The octal number 157 converts to decimal 111.
No. Octal numbers only use digits from 0 to 7. Digits 8 and 9 are invalid in octal format.
Octal numbers are commonly used in programming, computer permissions, and historical computing systems.