Octal Calculator

Perform arithmetic operations on octal (base 8) numbers. Add, subtract, multiply, divide, and calculate modulo with results in multiple formats.

The Octal Calculator performs arithmetic operations on octal (base 8) numbers. Octal uses digits 0-7 and is commonly used in computing, especially for Unix file permissions.

Enter the first octal number (using digits 0-7)
Select an arithmetic operator: +, −, ×, ÷, or %
Enter the second octal number
Click Calculate or press Enter to see results in all number bases

Full arithmetic operations: addition, subtraction, multiplication, division, modulo
Results displayed in binary, octal, decimal, and hexadecimal
Support for large numbers using BigInt
Quick examples for common octal calculations
Input validation ensures only valid octal digits (0-7)

What is octal?: Octal is a base-8 number system using digits 0-7. Each octal digit represents exactly 3 binary digits. For example, octal 17 equals decimal 15 (1×8 + 7).
Why is octal used?: Octal provides a compact way to represent binary data. It's commonly used in Unix/Linux file permissions (like chmod 755) and some programming contexts.
How do I convert octal to decimal?: Multiply each digit by its place value (powers of 8) and sum. For example: 17₈ = 1×8¹ + 7×8⁰ = 8 + 7 = 15₁₀.