Binary/Decimal/Hex Converter

Number bases: decimal (base 10) uses 0-9, binary (base 2) uses 0-1, hexadecimal (base 16) uses 0-9 and A-F. Binary 1011 = decimal 11. Each position is a power of the base. Hex FF = decimal 255.

Convert numbers between binary, decimal, octal, and hexadecimal. Instant conversion with reference table.

Input Number

Quick Reference

DecimalBinaryOctalHex
0000
1111
21022
81000108
10101012A
15111117F
16100002010
25511111111377FF

Number Base Guide

  • Binary (Base 2): Uses 0 and 1 only. Used in computers.
  • Octal (Base 8): Uses 0-7. Sometimes used in Unix permissions.
  • Decimal (Base 10): Standard human numbering system.
  • Hexadecimal (Base 16): Uses 0-9 and A-F. Common in programming.

How to Use

  1. Enter your value in the input field
  2. Click the Calculate/Convert button
  3. Copy the result to your clipboard

Frequently Asked Questions

What are different number bases?
Base (radix) is the number of unique digits used. Base 10 (decimal) uses 0-9. Base 2 (binary) uses 0-1. Base 16 (hexadecimal) uses 0-9 and A-F. Base 8 (octal) uses 0-7. Each position represents powers of the base.
How do I convert binary to decimal?
Multiply each digit by 2 raised to its position power (rightmost = position 0). Binary 1011 = 1×2³ + 0×2² + 1×2¹ + 1×2⁰ = 8 + 0 + 2 + 1 = 11 decimal. Read right to left with powers: 1, 2, 4, 8, 16, 32...
How do I convert decimal to binary?
Repeatedly divide by 2, record remainders. 13 decimal: 13÷2=6 r1, 6÷2=3 r0, 3÷2=1 r1, 1÷2=0 r1. Read remainders bottom-up: 1101 binary. Verify: 8+4+0+1 = 13.
Why is hexadecimal used in computing?
Hexadecimal is compact (1 hex digit = 4 bits) and human-readable. One byte (8 bits) = exactly 2 hex digits (00-FF). Memory addresses, colors (#FF5733), and binary data are cleaner in hex. 255 decimal = 11111111 binary = FF hexadecimal.
How do binary and hexadecimal relate?
Each hexadecimal digit represents exactly 4 binary digits. Convert each hex digit to 4-bit binary: 0x3F = 0011 1111. Conversely, group binary into 4-bit chunks from right: 11111111 = 1111 1111 = FF hex.

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