How to Understand Hexadecimal

Hexadecimal Clock
Hexadecimal Clock


Hexadecimal notation is used throughout the Web and computer systems to indicate values. One good example is the notation for color in HTML pages, these are given in hex.

Steps   [edit]

Understanding Hexadecimal Notation.

  1. To count in hexadecimal you need a method of notation for counting using base 16, rather than base 10. If you look at how to represent numbers using digits in base ten, you start counting at 0 and you indicating digits in the first column of the notation, when you reach ten you indicate a single digit in the second column and start over from 0 again in the first column. For example:
Decimal Notation
Zero 0  
One 1  
Two 2  
Three 3  
Four 4  
Five 5  
Six 6  
Seven 7  
Eight 8  
Nine 9  
Ten 1 0  
Eleven 1 1

Understand bases.

  1. The base of a number is what you count up to before you indicate a digit in the second column. Trouble is, we only have the numerals 0-9 for digits as our language is based on base 10 numbering (maybe because we have ten fingers). When we're counting in base 16 we use the letters a-f as notation for the remaining digits we need. The number eleven, for example, would be written as B. Counting to seventeen in Base 16 looks like this:
Hex Notation
Zero 0  
One 1  
Two 2  
Three 3  
Four 4  
Five 5  
Six 6  
Seven 7  
Eight 8  
Nine 9  
Ten A  
Eleven B  
Twelve C  
Thirteen D  
Fourteen E  
Fifteen F  
Sixteen 1 0
Seventeen 1 1
Eighteen 1 2

Find the hexadecimal notation for a given decimal number

  1. Find the closest even product of 16 for your number.
  2. Indicate the remainder using the table above.

    • For instance, 72 divided by 16 is 4, or 64, which leaves a remainder of 8. To write 72 in hexadecimal notation you would write 48, "four sixteens and eight remainder". Likewise to indicate the number 255 in hexadecimal you would write FF, because 15 sixteens are 240, so there are 15 sixteens in the left column, which leaves a remainder of 15 in the right column.