Number Base Converter

Binary, Octal, Decimal, and Hex Converter

A number base converter translates numbers between positional numeral systems: Binary (base 2), Octal (base 8), Decimal (base 10), and Hexadecimal (base 16). Understanding these conversions is a core skill in computer science, low-level programming, and digital electronics.

Type a value into any field and all other bases update in real time. Supports large numbers via BigInt and visually groups binary output into 4-bit and 8-bit blocks.

When to use each number base

• Binary (base 2): The native language of computers. Used in bitwise operations, CPU registers, flags, and network subnet masks.
• Octal (base 8): Used in Unix file permission modes (e.g., chmod 755 = 111 101 101 in binary) and some legacy systems.
• Decimal (base 10): Standard everyday number system. Used in most arithmetic, UI values, and high-level programming.
• Hexadecimal (base 16): Compact representation of binary data. Used in CSS colors (#FF5733), memory addresses, hash digests, and bytecode.

How to convert decimal to binary

1. Type any decimal number into the Decimal field.
2. The Binary, Octal, and Hex fields update instantly.
3. Enable visual binary grouping to see the result as 4-bit nibbles or 8-bit bytes.
4. Use the quick examples to explore common values: 255, 1023, 65535.

Common conversions reference

• 255 decimal = 1111 1111 binary = FF hex = 377 octal
• 16 decimal = 0001 0000 binary = 10 hex = 20 octal
• 256 decimal = 1 0000 0000 binary = 100 hex = 400 octal
• 1023 decimal = 11 1111 1111 binary = 3FF hex = 1777 octal