Free binary converter. Convert between binary, decimal, hexadecimal, and octal instantly. Shows all four number bases.
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Binary to Decimal Converter
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Formula
Formula
Binary to Decimal: Σ(bit × 2ⁿ) | Decimal to Binary: repeated division by 2
Binary uses only 0 and 1 (base 2). Hexadecimal uses 0-9 and A-F (base 16). Octal uses 0-7 (base 8). All are different representations of the same number.
Frequently Asked Questions
How do I convert binary to decimal?+
Multiply each bit by 2 to the power of its position (right to left, starting at 0), then sum. Example: 1011 = 1×8+0×4+1×2+1×1 = 11.
What is hexadecimal used for?+
Hex is used in programming, web colors (#FF5733), memory addresses, and computer science. It is more compact than binary.
What is 255 in binary?+
255 in decimal = 11111111 in binary = FF in hexadecimal. It is the maximum value of one byte (8 bits).