How do you convert octal to decimal?

Multiply each octal digit by its corresponding power of 8 (starting from 8⁰ on the right) and sum the results. For example, octal 75: (7×8¹) + (5×8⁰) = 56 + 5 = 61 in decimal.

What is octal 777 in decimal?

Octal 777 in decimal is 511. Calculation: (7×8²) + (7×8¹) + (7×8⁰) = 448 + 56 + 7 = 511.

Why convert octal to decimal?

While octal is compact and useful for Unix permissions, decimal is more intuitive for humans. Converting octal to decimal helps you understand the actual numeric value, which is useful for calculations, comparisons, and general understanding.

What do Unix file permissions mean in decimal?

Unix permissions like 755 mean: owner=7 (read+write+execute), group=5 (read+execute), others=5 (read+execute). In decimal, 755 represents the permission bits, but the actual numeric value is 493 in decimal (though this isn't typically used).

Is octal still commonly used?

Octal is mainly used for Unix file permissions today. Hexadecimal has largely replaced octal in most other contexts because it's more efficient (groups 4 bits vs 3 bits) and aligns better with byte boundaries.

Can I convert negative octal numbers?

Yes, but you need to know the representation format. For signed numbers, you might use sign-magnitude or complement representations. Our converter handles unsigned (positive) numbers by default.

🔢 Octal to Decimal Converter

Convert octal numbers to decimal instantly. Free online octal to decimal converter with detailed steps for quick and accurate conversions.

Octal Input

Conversion: Octal → Decimal

Octal to decimal conversion is frequently needed when working with Unix file permissions, legacy systems, or educational contexts where octal values need to be understood in human-readable decimal format. While octal is compact and useful for representing binary data in groups of three bits, decimal is more intuitive for most people. This converter provides instant, accurate conversions from octal to decimal.