### Part 1: What is Hexadecimal?

From Greek, hexadecimal is a word meaning "sixteen."

# 16

Hexa=6 (hexagonal, hexagram, etc.)

Decimal=10

In the hexadecimal system, 6 letters are added to the standard 0-9 Arabic Numerals, to give you a numbering system with base 16, instead of base ten.

Decimal: 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16

Hexadecimal: 0 1 2 3 4 5 6 7 8 9 A B C D E F 10

Count from 0 to 9, then count A, B, C, D, E, F.

Then you reach 10 (hexadecimal 10, which corresponds to decimal 16).

Count again: 11, 12, 13, 14, 15, 16, 17, 18 , 19, then use 1 and a letter: 1A, 1B, 1C, 1D, 1E, 1F.

Then you reach 20 (hexadecimal 20, which corresponds to decimal 32).

This continues forever. For instance, B0 in hexadecimal corresponds to 176 in decimal: (B[hex] * 16[decimal]) + (0 * 1). Since B is 11 in decimal, this equation becomes (11 * 16) + (0 * 1) = 11 * 16 = 176.

Here are another few examples:

 Hex. = Hex. equation = Decimal equation = Decimal C8 = (C * 10) + (8 * 1) = (12 * 16) + (8 * 1) = 200 FF = (F * 10) + (F * 1) = (15 * 16) + (15 * 1) = 255 100 = (1 * 10 * 10) + (0 * 10) + (0 * 1) = (1 * 16 * 16) + (0 * 16) + (0 * 1) = 256

To convert from decimal to hexadecimal, reverse this procedure. For instance, 178 in decimal corresponds to B2 in hexadecimal: 178 = (11 * 16) + (2 * 1) = (B * 10[hex.]) + (2 * 1) = B2. Here are another few examples:

 Decimal = Decimal equation = Hex. equation = Hex. 48 = (3 * 16) + (0 * 1) = (3 * 10) + (0 * 1) = 30 513 = (2 * 16 * 16) + (0 * 16) + (1 * 1) = (2 * 10 * 10) + (0 * 10) + (1 * 1) = 201 1,000 = (3 * 16 * 16) + (14 * 16) + (8 * 1) = (3 * 10 * 10) + (E * 10) + (8 * 1) = 3E8

Here are some more numbers in hexadecimal and decimal. Try converting one form to the other, and back again, until you are comfortable with the process.

 Hex. Dec. . Hex. Dec. . Hex. Dec. 0 0 10 16 C8 200 1 1 11 17 F0 240 2 2 19 25 FF 255 9 9 1A 26 100 256 A 10 1B 27 3E8 1,000 B 11 1F 31 1000 4,096 C 12 20 32 10000 65,536 D 13 32 50 100000 1,048,576 E 14 64 100 FFFFFF 16,777,215 F 15 A0 160 1000000 16,777,216

If you would rather let the computer compute hexadecimal numbers, you can try this automatic converter.

Decimal:

Hex:

For simplicity, the word "hexadecimal" is often shortened to "hex".

Technical Information for the Curious: