Octal to Decimal Converter

Convert octal (base-8) numbers to decimal instantly. Free online octal to decimal calculator with examples.

💡 Enter octal → get decimal. Example: "755" → "493".

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How to Convert Octal to Decimal

Step-by-step guide with examples

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What is Octal to Decimal Conversion?

Octal to decimal conversion transforms base-8 numbers (digits 0-7) into base-10 numbers. Multiply each octal digit by 8 raised to the power of its position (right to left, starting from 0) and sum the results.

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How to Convert Octal to Decimal Step-by-Step

1. Write the octal number. 2. Assign powers of 8 to each position from right to left. 3. Multiply each digit by its power of 8. 4. Add all products. Example: 755 = 7×64 + 5×8 + 5×1 = 448+40+5 = 493

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Common Use Cases

• Interpreting Unix file permissions. • Converting octal constants in C/C++ code. • Understanding legacy computing formats. • Number system conversion exercises.

Frequently Asked Questions

2 common questions answered

2 Questions2 AnswersClick to expand
Q1How to convert octal to decimal?
Multiply each octal digit by 8^position and add all results. Example: 755 = 7×8² + 5×8¹ + 5×8⁰ = 448+40+5 = 493.
Q2What is 777 octal in decimal?
777 octal = 7×64 + 7×8 + 7×1 = 448+56+7 = 511 decimal.