Convert between number bases and perform arithmetic in different bases
Simply type a number in any base field, and it will automatically convert to all other bases.
Binary: Uses only 0 and 1
Octal: Uses digits 0-7
Decimal: Uses digits 0-9 (our everyday numbers)
Hexadecimal: Uses digits 0-9 and letters A-F (where A=10, B=11, ..., F=15)
A number base (or radix) determines how many unique digits are used to represent numbers.
In base b, each position represents a power of b:
Binary (base 2): Foundation of all digital computing. Computers use binary because electronic circuits have two states (on/off).
Hexadecimal (base 16): Compact representation of binary. Each hex digit represents exactly 4 binary digits, making it easier for humans to read large binary numbers.
Octal (base 8): Another compact binary representation (3 binary digits = 1 octal). Still used in Unix file permissions.
Hexadecimal uses 16 digits: 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, A, B, C, D, E, F
Letter values:
Example: 2A = 2×16 + 10 = 42 in decimal
You can use any base from 2 to 36. For bases larger than 10, letters are used:
Web colors: #FF0000 is red in hexadecimal (R=255, G=0, B=0)
File permissions: chmod 755 uses octal (rwxr-xr-x)
IPv6 addresses: Use hexadecimal (2001:0db8:85a3::8a2e:0370:7334)
Memory addresses: Usually shown in hexadecimal
Assembly language: Uses hexadecimal for instructions and data