Every letter of the English alphabet in 8-bit binary — uppercase, lowercase, and beyond
| Letter | Decimal | Binary | Letter | Decimal | Binary | |
|---|---|---|---|---|---|---|
| A | 65 | 01000001 | N | 78 | 01001110 | |
| B | 66 | 01000010 | O | 79 | 01001111 | |
| C | 67 | 01000011 | P | 80 | 01010000 | |
| D | 68 | 01000100 | Q | 81 | 01010001 | |
| E | 69 | 01000101 | R | 82 | 01010010 | |
| F | 70 | 01000110 | S | 83 | 01010011 | |
| G | 71 | 01000111 | T | 84 | 01010100 | |
| H | 72 | 01001000 | U | 85 | 01010101 | |
| I | 73 | 01001001 | V | 86 | 01010110 | |
| J | 74 | 01001010 | W | 87 | 01010111 | |
| K | 75 | 01001011 | X | 88 | 01011000 | |
| L | 76 | 01001100 | Y | 89 | 01011001 | |
| M | 77 | 01001101 | Z | 90 | 01011010 |
Notice the pattern: uppercase letters all start with 010 followed by the letter's position in the alphabet plus 64 in binary. A is 1st letter: 64+1=65 = 01000001. Z is 26th: 64+26=90 = 01011010.
Lowercase letters use ASCII codes 97-122 and all start with 011. a = 97 = 01100001. The lowercase binary is the uppercase binary with the third bit from the left flipped from 0 to 1. A = 01000001, a = 01100001. This 32-value offset (97-65=32) is a deliberate design choice in ASCII that makes case conversion trivial: toggle one bit.
| Char | Binary | Char | Binary | |
|---|---|---|---|---|
| 0 | 00110000 | Space | 00100000 | |
| 9 | 00111001 | ! | 00100001 | |
| . | 00101110 | ? | 00111111 | |
| , | 00101100 | @ | 01000000 |
For a complete chart, see our ASCII binary reference table. To convert full sentences to binary instantly, use the free binary translator.