Decimal, binary, hexadecimal and octal.
Number bases are fundamental to computing and digital electronics. While humans use base-10 (decimal) for everyday arithmetic, computers operate internally in base-2 (binary). Programmers frequently work with base-16 (hexadecimal) because it compactly represents binary data — each hex digit corresponds to exactly 4 bits. Base-8 (octal) is less common today but still appears in Unix file permissions.
This converter lets you enter a number in any of the four bases and instantly see its equivalent in all others. It uses JavaScript's BigInt for accuracy with large numbers.
The decimal number 255 is 11111111 in binary, FF in hexadecimal, and 377 in octal. The decimal number 42 is 101010 in binary — famously the "Answer to the Ultimate Question of Life, the Universe, and Everything" in The Hitchhiker's Guide to the Galaxy.
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