Binary to Decimal Converter

Convert between binary, decimal, hexadecimal, and octal number systems.

Result

Binary

Decimal

Hexadecimal

Octal

How It Works

Enter a number in any base (binary, decimal, hex, or octal) and see it instantly converted to all other bases with step-by-step working.

**Binary to Decimal Converter — Master Number Base Conversion**

Computers speak in binary (base 2). Humans prefer decimal (base 10). Hexadecimal (base 16) bridges the two for programmers. Our multi-base converter handles all four common number systems with full step-by-step workings.

**The Four Number Bases**

**Binary (Base 2)**
Digits: 0, 1
Used by: Computer hardware, digital logic, low-level programming

**Octal (Base 8)**
Digits: 0–7
Used by: Unix file permissions (chmod 755), some legacy systems

**Decimal (Base 10)**
Digits: 0–9
Used by: Everyday human counting

**Hexadecimal (Base 16)**
Digits: 0–9, A–F (A=10, B=11, C=12, D=13, E=14, F=15)
Used by: Colour codes (#FF5733), memory addresses, debugging

**Conversion Method: Binary to Decimal**

Each binary digit represents a power of 2, from right to left:

1011₂ = 1×2³ + 0×2² + 1×2¹ + 1×2⁰
= 8 + 0 + 2 + 1 = 11₁₀

**Conversion Method: Decimal to Binary**

Repeated division by 2:
11 ÷ 2 = 5 remainder 1
5 ÷ 2 = 2 remainder 1
2 ÷ 2 = 1 remainder 0
1 ÷ 2 = 0 remainder 1
Read remainders from bottom to top: 1011

**Hex and RGB Colours**

The hex colour #FF5733 means:
- FF = 255 (red), 57 = 87 (green), 33 = 51 (blue)
This is RGB(255, 87, 51) — an orange-red colour.

**Binary in Computing**

- 1 bit = one binary digit (0 or 1)
- 8 bits = 1 byte (values 0–255)
- 16 bits = 1 word (0–65,535)
- 32 bits = 0–4,294,967,295
- 64 bits = modern computing standard

Frequently Asked Questions

Multiply each binary digit by 2 raised to its position power (right to left, starting at 0), then sum all results. Example: 1011 = 1×8 + 0×4 + 1×2 + 1×1 = 11.
Hex is used for colour codes in web design (#RRGGBB), memory addresses in debugging, IPv6 addresses, and representing binary data more compactly (1 hex digit = 4 bits).
11111111₂ = 255₁₀ = FF₁₆. This is why colours in RGB go from 0 to 255 — they're stored as 8-bit numbers.
755 in octal = 111 101 101 in binary = rwxr-xr-x. Each set of 3 bits represents read, write, execute permissions for owner, group, and others.
Two's complement is the standard method computers use to represent negative binary numbers. Flip all bits and add 1. Example: -5 in 8-bit = flip(00000101) + 1 = 11111010 + 1 = 11111011.