Octal to Decimal Converter
Convert octal (base 8) numbers to decimal (base 10)
Decimal Result
42
Step-by-Step Conversion
| Digit | Position | Power of 8 | Value |
|---|---|---|---|
| 5 | 1 | 8^1 = 8 | 5 × 8 = 40 |
| 2 | 0 | 8^0 = 1 | 2 × 1 = 2 |
Sum: 40 + 2 = 42
Common Octal Values
About Octal
Octal (base 8) uses digits 0-7. Each octal digit represents exactly 3 binary bits.
Historically used in computing, especially on systems with 12, 24, or 36-bit words.
Still used in Unix file permissions (e.g., chmod 755).
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Editorial Note
MyCalcBuddy Editorial Team
This page is maintained as an educational calculator reference.
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Formula Source: NIST Guide to SI Units
by National Institute of Standards
🔄Last reviewed: May 2026
✓Formula checks are based on standard references and internal QA review.