Only digits 0-7 allowed
Octal uses digits 0-7, providing a compact representation primarily used in Unix file permissions and legacy computing systems.
Decimal uses digits 0-9 and is the standard number system for everyday mathematics, business calculations, and human-readable numbers.
Understand and calculate Unix file permissions where octal 755 means rwxr-xr-x, helping system administrators manage file access control.
Essential for working with older computer systems, mainframes, and analyzing output from legacy applications that use octal notation.
Helps students and professionals understand different number systems, positional notation, and mathematical relationships between bases.
Used for interpreting system logs, error codes, and converting octal values from various tools into understandable decimal format.
Input your octal number using only digits 0-7 in the converter field.
System multiplies each digit by its power of 8 and sums the results.
Copy your decimal result for use in calculations or applications.
Multiply each octal digit by its corresponding power of 8 and sum the results. For example, octal 755 = (7×8²) + (5×8¹) + (5×8⁰) = 448 + 40 + 5 = 493 decimal.
Octal numbers use only digits 0-7. If you see digits 8 or 9 in a number, it's not a valid octal number. Our converter will alert you if invalid digits are entered.
Converting octal to decimal is essential for understanding Unix file permissions (chmod values), legacy system outputs, and translating compact octal notation into human-readable decimal numbers.
Unix permissions use 3-digit octal numbers where each digit represents read(4), write(2), execute(1) permissions. For example, octal 755 means rwxr-xr-x permissions, which equals decimal 493.
Yes, octal to decimal conversion is mathematically exact with no precision loss. Both number systems represent the same integer values, just in different bases (8 vs 10).