This page lists decimal, binary, octal and hexadecimal numbers. In addition, the page lists numbers in several unusual number systems: unary (base-1), ternary (or trinary, base-3), quaternary (base-4), quinary (base-5), senary (base-6), septenary (base-7), undecimal (base-11), dozenal (or duodecimal, base-12), vicesimal (base-20) and hexatrigesimal (base-36). BCD numbers and bijective bases are also covered.
Decimal (base-10), binary (base-2), octal (base-8) and hexadecimal (base-16) numbers are commonly used in computing. Binary coded digitals (BCD) have also been used in computing. The other number systems are far less common.
Dec, Bin, Oct and Hex
Binary numbers can be written as
11111111'b. For clarity, binary numbers can be grouped. On this page, the groups are 4 bits each. Octals are often written with a zero prefix (
07777). Hexadecimal numbers can be written in several ways:
0 to in decimal, binary, octal and hexadecimal.
Base-3 to Base-7
|3||Ternary or trinary||012|
0 to in base-3, base-4, base-5, base-6 and base-7.
Base-11, 12, 20 and 36
|12||Dozenal or duodecimal||0123456789AB|
0 to in base-11, base-12, base-20 and base-36.
0 to in decimal and unary.
Binary Coded Decimal
|2||Binary Coded Decimal (BCD)||01|
Binary Coded Decimal represents each decimal digit in 4 bits. BCD comes in several variants. This variant is known as Simple BCD or BCD 8421.
0 to in BCD and regular binary.
In bijective bases there is no zero digit. Excel uses bijective base-26 for column names.
0 to in bijective bases.