— Binary/Decimal Converter

Free Binary/Decimal Converter

Quick Tips

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Convert numbers between binary (base 2) and decimal (base 10).

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Examples

Input
1101 (binary)
Output
13 (decimal)
Input
255 (decimal)
Output
11111111 (binary)
Input
1024 (decimal)
Output
10000000000 (binary)
Input
10101010 (binary)
Output
170 (decimal)

Why Use This Tool?

What problems does this solve?

Working with low-level programming, bit manipulation, or understanding computer architecture requires binary fluency. This tool makes conversions instant.

Common use cases:

  • Learning binary for computer science courses
  • Debugging bit manipulation code
  • Understanding memory addresses and sizes
  • Working with binary protocols and file formats
  • Calculating permissions (Unix file modes)

Who benefits from this tool?

Computer science students. Programmers working with bitwise operations. System administrators setting permissions. Anyone learning computing fundamentals.

Privacy first: All conversion happens locally in your browser. Your numbers never leave your device.

Frequently Asked Questions

Electronic circuits have two reliable states: on and off. Binary (0 and 1) maps perfectly to this. More states would be harder to distinguish reliably and make circuits more complex.

Multiply each bit by 2 raised to its position (rightmost is position 0). Add all results. For 1101: 1×8 + 1×4 + 0×2 + 1×1 = 13.

For unsigned: 255 (11111111). For signed (two's complement): 127 (positive) to -128 (negative). The leading bit indicates sign in signed representation.

A way to represent negative numbers in binary. Flip all bits and add 1 to get the negative. For example, -1 in 8-bit two's complement is 11111111.

Binary addressing means memory and storage naturally come in powers of 2. 2^10=1024 (KB), 2^20=1048576 (MB), etc. This aligns with how binary counting works.

The 0x prefix indicates hexadecimal, not binary. Binary often uses 0b prefix (0b1101). However, both relate to binary since each hex digit equals 4 binary bits.