Number Base Converter
Convert numbers between binary (base 2), octal (base 8), decimal (base 10), and hexadecimal (base 16) instantly.
What Are Number Bases?
A number base (or radix) is the number of unique digit symbols used in a positional number system. The decimal system used in everyday life is base 10, using digits 0-9. Binary (base 2) uses only 0 and 1, because the transistors inside computers have exactly two states: on and off. Hexadecimal (base 16) uses digits 0-9 and letters A-F. Each digit in hexadecimal represents exactly 4 binary bits, making it compact shorthand for binary values.
Converting between bases is a matter of understanding place value. In decimal, each digit position represents a power of 10. In binary, each position represents a power of 2. In hexadecimal, each position represents a power of 16. The decimal number 255 is FF in hexadecimal and 11111111 in binary.
When to Convert Between Number Bases
Developers encounter number base conversion daily. Colour codes in CSS and design tools are expressed in hexadecimal. Unix file permissions use octal notation, where 7 means read+write+execute and 5 means read+execute. Memory addresses in debuggers and disassemblers are shown in hexadecimal. Network masks and IP addresses are manipulated using binary and hexadecimal arithmetic.
Computer science students work with base conversion when learning how processors represent integers, how floating-point numbers are encoded in IEEE 754, and how bitwise operations manipulate individual bits. Embedded systems developers set GPIO pin states, configure registers, and work with hardware addresses entirely in binary and hexadecimal. A number base converter handles these conversions in both directions across any combination of bases.
How to Use Number Base Converter
- 1
Click into any of the four base fields - Decimal, Binary, Octal, or Hexadecimal.
- 2
Type your number in that field.
- 3
All other base representations update automatically.
- 4
Click the copy icon next to any field to copy that value to your clipboard.
Frequently Asked Questions
How do I convert binary to decimal?
Enter your binary number in the Binary field and the Decimal value updates instantly. For example, 11111111 in binary is 255 in decimal.
How do I convert decimal to hexadecimal?
Enter your decimal number in the Decimal field and the Hexadecimal field updates automatically. For example, 255 decimal is FF in hex.
What is hexadecimal used for?
Hexadecimal (base 16) is widely used in programming and computing to represent binary data in a compact format. It is used for memory addresses, colour codes (like #FF5733), and binary file data.