Short, accurate guides to how binary works, with worked examples and practice problems you can check in our converters.
Start here
If you are new to binary, read the guides in this order. Each one builds on the last and links to a converter so you can check your own working.
- What is binary? Bits, bytes and place values.
- Decimal to binary using division by 2.
- Binary to decimal using place values.
- Binary to text using ASCII and UTF-8.
- Binary arithmetic: addition, subtraction and multiplication.
All guides
What Is Binary?Base 2, bits, bytes and why computers use itHow to Convert Binary to TextStep-by-step guideHow to Convert Decimal to BinaryStep-by-step guideHow to Convert Binary to DecimalPlace values and worked examplesBinary Addition and SubtractionRules and worked examples
Tools to practise with
Text to BinaryTurn words and sentences into binary codeBinary to TextDecode 0s and 1s into readable textDecimal to BinaryConvert numbers to base 2 with the division stepsBinary CalculatorAdd, subtract, multiply, divide and use logic operators
Reference tables
Keep the ASCII binary table and the binary alphabet chart handy while you practise.
Why learn binary?
Binary is the foundation of how every computer stores and processes information. Understanding it makes programming, networking, electronics and data formats easier to grasp, and it is a regular topic in computer science courses and exams.