ASCII Table

ASCII is an acronym for American Standard Code for Information Interchange. Yeah, that doesn’t really tell us much about what an ASCII code is, or why we should care about an ASCII table.

For that, we need to remember that computers only understand numbers. And only binary numbers at that. When you press the A key on your keyboard, we need a way for your computer to know what key was pressed. And since it doesn’t understand letters, we have to use numbers.

If you scroll down on the ASCII table below and find the capital letter A you’ll see that it has an ASCII value of 65, which is 0100 0001 in binary. That number is sent from your keyboard to your computer and the computer interprets it as an A. The same thing happens in data files. It’s the number that’s ultimately needed, not the character.

And if you’d like a little more information on ASCII, head on over to Wikipedia.

ASCII Table

Here you’ll find a list of the first 127 ASCII codes that your computer knows how to work with. We’re no longer limited to just 127, but when people talk about ASCII tables, this is usually the list they’re talking about.

You can probably skip over the first 31. They’re system codes that tell the computer how to do things, but don’t typically show up on screen. There are a few interesting ones in there though. For example, pressing the enter key on your keyboard sends the code 13.

Visible characters start at 32 with space. Okay, so I guess space really isn’t a visible character.

If you’re using this ASCII table for an intro to programming course you probably really only have to memorize 3 or 4 different numbers. The first one is space, which is code 32. Then you’ll want to remember lower case a (97), capital A (65) and zero (48). From there you can figure out the other letters and numbers. Since the letters and number are sequential you can work out the rest. For example, a lower case d is 100 – 3 characters after lower case a.

CHARACTER	DECIMAL	BINARY	OCTAL	HEX
(null)	0	0	0	0
(start of heading)	1	1	1	1
(start of text)	2	10	2	2
(end of text)	3	11	3	3
(end of transmission)	4	100	4	4
(enquiry)	5	101	5	5
(acknowledge)	6	110	6	6
(bell)	7	111	7	7
(backspace)	8	1000	10	8
(horizontal tab)	9	1001	11	9
(new line)	10	1010	12	A
(vertical tab)	11	1011	13	B
(new page)	12	1100	14	C
(carriage return)	13	1101	15	D
(shift out)	14	1110	16	E
(shift in)	15	1111	17	F
(data link escape)	16	10000	20	10
(device control 1)	17	10001	21	11
(device control 2)	18	10010	22	12
(device control 3)	19	10011	23	13
(device control 4)	20	10100	24	14
(negative acknowledge)	21	10101	25	15
(synchronous idle)	22	10110	26	16
(end of trans block)	23	10111	27	17
(cancel)	24	11000	30	18
(end of medium)	25	11001	31	19
(substitute)	26	11010	32	1A
(escape)	27	11011	33	1B
(file separator)	28	11100	34	1C
(group separator)	29	11101	35	1D
(record separator)	30	11110	36	1E
(unit separator)	31	11111	37	1F
(SPACE)	32	100000	40	20
!	33	100001	41	21
”	34	100010	42	22
#	35	100011	43	23
$	36	100100	44	24
%	37	100101	45	25
&	38	100110	46	26
‘	39	100111	47	27
(	40	101000	50	28
)	41	101001	51	29
*	42	101010	52	2A
+	43	101011	53	2B
,	44	101100	54	2C
–	45	101101	55	2D
.	46	101110	56	2E
/	47	101111	57	2F
0	48	110000	60	30
1	49	110001	61	31
2	50	110010	62	32
3	51	110011	63	33
4	52	110100	64	34
5	53	110101	65	35
6	54	110110	66	36
7	55	110111	67	37
8	56	111000	70	38
9	57	111001	71	39
:	58	111010	72	3A
;	59	111011	73	3B
<	60	111100	74	3C
=	61	111101	75	3D
>	62	111110	76	3E
?	63	111111	77	3F
`	64	1000000	100	40
A	65	1000001	101	41
B	66	1000010	102	42
C	67	1000011	103	43
D	68	1000100	104	44
E	69	1000101	105	45
F	70	1000110	106	46
G	71	1000111	107	47
H	72	1001000	110	48
I	73	1001001	111	49
J	74	1001010	112	4A
K	75	1001011	113	4B
L	76	1001100	114	4C
M	77	1001101	115	4D
N	78	1001110	116	4E
O	79	1001111	117	4F
P	80	1010000	120	50
Q	81	1010001	121	51
R	82	1010010	122	52
S	83	1010011	123	53
T	84	1010100	124	54
U	85	1010101	125	55
V	86	1010110	126	56
W	87	1010111	127	57
X	88	1011000	130	58
Y	89	1011001	131	59
Z	90	1011010	132	5A
[	91	1011011	133	5B
\|	92	1011100	134	5C
]	93	1011101	135	5D
^	94	1011110	136	5E
_	95	1011111	137	5F
`	96	1100000	140	60
a	97	1100001	141	61
b	98	1100010	142	62
c	99	1100011	143	63
d	100	1100100	144	64
e	101	1100101	145	65
f	102	1100110	146	66
g	103	1100111	147	67
h	104	1101000	150	68
i	105	1101001	151	69
j	106	1101010	152	6A
k	107	1101011	153	6B
l	108	1101100	154	6C
m	109	1101101	155	6D
n	110	1101110	156	6E
o	111	1101111	157	6F
p	112	1110000	160	70
q	113	1110001	161	71
r	114	1110010	162	72
s	115	1110011	163	73
t	116	1110100	164	74
u	117	1110101	165	75
v	118	1110110	166	76
w	119	1110111	167	77
x	120	1111000	170	78
y	121	1111001	171	79
z	122	1111010	172	7A
{	123	1111011	173	7B
		124	1111100	174	7C
}	125	1111101	175	7D
~	126	1111110	176	7E
(delete)	127	1111111	177	7F