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Number Base Converter

Convert numbers between binary, octal, decimal, hexadecimal and any base (2-36). Free online number base converter.

Custom Base Conversion

from base 10 to

What is Number Base Converter?

A number base converter transforms numbers between different numeral systems: binary (base 2), octal (base 8), decimal (base 10), hexadecimal (base 16), and any custom base from 2 to 36. Different bases are used in computing — binary for machine code, hex for color codes and memory addresses, and octal for Unix file permissions.

How to Use

  1. Enter a number in the input field
  2. Select the source base (binary, octal, decimal, hex, or custom)
  3. Conversions to all other bases appear instantly below
  4. Use the copy button next to each result to copy it

Examples

Decimal to binary and hex

Input255 (decimal)
OutputBinary: 11111111 | Hex: FF | Octal: 377

Hex color to decimal

InputFF5733 (hex)
OutputDecimal: 16734 symbols | Binary: 111111110101011100110011

Frequently Asked Questions

What number bases are commonly used in programming?

Binary (base 2) for bitwise operations, octal (base 8) for Unix file permissions, decimal (base 10) for everyday math, and hexadecimal (base 16) for color codes (#FF5733), memory addresses, and byte values.

How do I prefix different bases in code?

In most programming languages: 0b for binary (0b1010), 0o for octal (0o12), 0x for hex (0xFF), and no prefix for decimal (255). JavaScript, Python, and C all support these prefixes.

What is base 36 used for?

Base 36 uses digits 0-9 and letters A-Z, giving the most compact representation using alphanumeric characters. It's used for URL shorteners, generating compact IDs, and encoding large numbers in limited-character formats.