Learn Binary
Start with what binary code is, then learn to read it and do arithmetic with it. Each guide has worked examples and a tool to check your answers, and the charts are there when you need to look something up.
Guides, in order
- 01What Is Binary Code?
Learn what binary code is, why computers use 0s and 1s, and how text and numbers become binary, with interactive examples.
- 02How to Read Binary
Learn how to read binary code by hand in 3 steps: split into bytes, convert to decimal, look up ASCII. Practice with examples.
- 03Binary Addition
Learn binary addition: the four rules, carrying explained column by column, a worked example and 10 practice problems that check your answers.
- 04Binary Subtraction
Binary subtraction explained: the borrowing rules, a worked example, and subtracting by adding the 2's complement, with practice problems.
Charts and worksheets
- Binary Alphabet Chart
Full binary alphabet chart for uppercase and lowercase letters A to Z, numbers and symbols, with decimal and hex. Searchable and printable.
- ASCII Table
Complete ASCII table 0 to 127 with binary, decimal, hex and character columns. Searchable and printable.
- Binary Numbers Chart
Binary numbers chart from 0 to 255 with decimal and hex, plus 1 to 100 on one page. Searchable and printable, with the steps to read any row.
- Binary Worksheets
Free printable binary worksheets with answer keys: decode words, convert numbers and add binary. Pick a level and print, or save as PDF.
A study plan
- 01
Learn the idea
Read what binary code is: bits, bytes and place values that double from right to left.
- 02
Decode a word
Follow how to read binary and work through its practice words.
- 03
Do the arithmetic
Add and subtract with carries and borrows, then check each answer with the calculator in the guide.
Try it as you read
Paste binary to decode it, or type text to encode it. The translator works out which way to go.
Binary translator
Binary
Frequently asked questions
How long does it take to learn binary?
Reading a byte rests on one idea: place values that double from right to left. With the how to read binary guide and a few practice words, you can decode a message the same day.
Do I need math to learn binary?
Only adding and doubling. Each place value is double the one to its right, converting binary to decimal is adding those values, and binary addition uses four short rules.
What should I learn after binary?
Hexadecimal, which writes every 4 bits as one digit and is how programmers read bytes. After that, two's complement, the way computers store negative numbers. Both have converters on this site.