Binary to Octal Converter

Convert binary numbers to octal and octal to binary instantly. Also shows decimal and hexadecimal. Free browser-based tool.

How to Use

  1. 1 Select Binary → Octal to convert a binary number to octal, or Octal → Binary for the reverse
  2. 2 Enter your binary number (e.g. 1010) or octal number (e.g. 12)
  3. 3 Click Convert to see the result along with decimal and hexadecimal representations

Use Cases

Programming

Convert binary values to octal for compact representation in Unix file permissions and legacy systems.

Computer Science Learning

Practice number base conversions between binary, octal, decimal, and hex to understand how different bases relate.

Unix Permissions

Convert binary permission bits (e.g. 111 101 101) to octal notation (755) used by chmod commands.

FAQ

Group the binary digits into sets of 3 from the right, then convert each group to its octal digit. For example, 110101 → 110 101 → 6 5 → octal 65.

Each octal digit (0–7) represents exactly 3 binary bits, making octal a natural shorthand for binary. This is why octal is commonly used in Unix file permissions.

This tool handles standard JavaScript safe integers (up to 2^53 - 1), which covers all practical use cases.

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