Last verified: September 24, 2026.
There is no separate binary alphabet. Every letter your computer stores is a number, and that number is written in base 2. The letter A is 65, which in eight bits is 01000001. Lowercase a is 97, or 01100001. Learn how those numbers are built and you can read any of it.
This guide covers the place values, the full character table, a worked conversion in both directions, and what happens with accents and emoji. You can check your answers in our binary code translator, which converts text and binary as you type.
Where the binary alphabet comes from
Computers store characters using a code chart. The original one is ASCII, defined in RFC 20, which suggests "the use of standard 7-bit ASCII embedded in an 8 bit byte whose high order bit is always 0". That's why the binary for a letter has eight digits but always starts with 0.
ASCII covers unaccented English, digits and punctuation. Everything else comes from Unicode, which as the consortium puts it "provides a unique number for every character, no matter what the platform". So the binary alphabet you see online is really ASCII, and ASCII is the first 128 characters of Unicode.
One more piece of vocabulary: a bit is a single 0 or 1, and eight bits make a byte. NIST puts it plainly: one byte equals 8 bits.
The place values that make it readable
Decimal columns go 1, 10, 100, 1000. Binary columns double instead, as NC State's engineering course notes put it: binary place values are powers of 2, starting at 2⁰ on the right.
For a byte, the eight columns are:
| 128 | 64 | 32 | 16 | 8 | 4 | 2 | 1 |
|---|---|---|---|---|---|---|---|
| 0 | 1 | 0 | 0 | 0 | 0 | 0 | 1 |
Add up the columns with a 1 in them: 64 + 1 = 65. Look 65 up in ASCII and you get the letter A. That single row is the whole trick behind the binary alphabet.
Reading binary, step by step
Take 01101000. Write the place values above it, then add the ones that are switched on: 64 + 32 + 8 = 104. Character 104 is lowercase h.
Going the other way, start with the letter and subtract. For lowercase i, the code is 105. The biggest place value that fits is 64, leaving 41. Then 32 fits, leaving 9. Then 8, leaving 1. Then 1, leaving nothing. Mark those columns with a 1 and the rest with 0 and you get 01101001.
Put the two together and "hi" is 01101000 01101001.
The binary alphabet in full
Uppercase letters run from 65 to 90, lowercase from 97 to 122. The space is 32, and it's the character most people forget when they write out a sentence.
| Letter | Binary | Letter | Binary | Letter | Binary |
|---|---|---|---|---|---|
| A | 01000001 | J | 01001010 | S | 01010011 |
| B | 01000010 | K | 01001011 | T | 01010100 |
| C | 01000011 | L | 01001100 | U | 01010101 |
| D | 01000100 | M | 01001101 | V | 01010110 |
| E | 01000101 | N | 01001110 | W | 01010111 |
| F | 01000110 | O | 01001111 | X | 01011000 |
| G | 01000111 | P | 01010000 | Y | 01011001 |
| H | 01001000 | Q | 01010001 | Z | 01011010 |
| I | 01001001 | R | 01010010 | space | 00100000 |
Digits sit lower down the chart: 0 is 00110000 and the rest follow in order up to 9 at 00111001. Common punctuation includes the period at 00101110, the comma at 00101100 and the exclamation mark at 00100001.
The lowercase shortcut worth knowing
Compare A at 01000001 with a at 01100001. Only the third digit changed. That's the 32 column, and it's the difference between 65 and 97 for every letter in the alphabet.
So the binary alphabet is really one table, not two, and you never need to memorize the lowercase half. Take the uppercase code, flip that one bit on, and you have the lowercase version. Flip it off to go back.
Write your name in binary
Four steps with the binary alphabet table above, using Max as the example.
- Split the name into characters: M, a, x.
- Look up each code: M is 77, a is 97, x is 120.
- Convert each to eight bits: 01001101, 01100001, 01111000.
- Join them with spaces so each byte stays readable.
Max is 01001101 01100001 01111000. For a full sentence, remember the space at 00100000 between words. "I love you" comes out as 01001001 00100000 01101100 01101111 01110110 01100101 00100000 01111001 01101111 01110101, which is 80 bits, or 10 bytes.
Accents and emoji need more than one byte
ASCII stops at 127, so é, 漢 and 👍 are not in it. Modern text uses UTF-8, defined in RFC 3629, which encodes characters in a varying number of octets depending on the character's value: one byte for the ASCII range, two, three or four for everything above it.
| Character | Bytes | Binary |
|---|---|---|
| A | 1 | 01000001 |
| é | 2 | 11000011 10101001 |
| 👍 | 4 | 11110000 10011111 10010001 10001101 |
This is also why a file of English text is smaller than the same text in Japanese, and why an emoji costs four times as much storage as a letter. If storage sizes interest you, our guide to the best phone under $500 covers what those gigabytes hold in practice.
Notice that the multi-byte versions start with 1, not 0. That leading pattern is how software knows a character continues into the next byte. The rule from RFC 3629 keeps the old system intact: a US-ASCII character is still encoded in a single byte with its normal value, so plain English text is identical in both.
Practice, with answers
Cover the right column and work them out with the place values. If the binary alphabet has landed, these take a minute.
| Question | Answer |
|---|---|
| 01001000 01001001 | HI |
| 01100011 01100001 01110100 | cat |
| Write YES in binary | 01011001 01000101 01010011 |
| What is 01000010 in decimal? | 66, the letter B |
| Turn 01010100 into lowercase | 01110100, the letter t |
Paste any of them into the translator to check, or type a word and watch the bits appear. Working through this on a school machine? Our comparison of the difference between a laptop and a Chromebook covers what each one can run for coursework. If you also write essays, our words to pages converter handles the other kind of counting, and the rest of our free tools are on one page.
Frequently asked questions
What is the binary alphabet?
It's the set of binary codes for letters, taken from ASCII. Each letter has a number, and that number is written in base 2 across eight bits. A is 65 or 01000001, and Z is 90 or 01011010.
What is my name in binary?
Convert each letter with the table above, keep the codes in order, and use 00100000 for a space. Max becomes 01001101 01100001 01111000.
Why is every letter eight digits long?
Because a byte is eight bits, and ASCII only needs seven of them, so the eighth is padded with a leading zero. Dropping that zero is the most common mistake in homework answers.
What does 8 bit binary mean?
It means each character is written with eight digits, giving 256 possible values from 00000000 to 11111111. Letters sit between 65 and 122, and ASCII as a whole fills the first 128 values.
How do I write lowercase letters in binary?
Take the uppercase code and add 32, which flips the third digit from 0 to 1. A at 01000001 becomes a at 01100001.
