Number Base Converter Tool
Convert between binary, octal, decimal, and hexadecimal. Supports negative numbers and bit width.
Options
Convert
Decimal
DEC
Binary
BIN
Octal
OCT
Hexadecimal
HEX
Custom
Base
About Number Bases
BINUses only 0 and 1. Used in computer processing
OCTUses digits 0-7. Used in Unix file permissions
DECUses digits 0-9. Everyday number system
HEXUses 0-9 and A-F. Used in color codes and memory addresses
How to Use
1
Enter a value
Enter the number you want to convert. Negative numbers are also supported.
2
Auto convert
The value is automatically converted to other bases as you type.
3
Set options
Configure bit width, prefix display, and 4-digit separator.
About This Tool
A free online tool to convert between binary, octal, decimal, and hexadecimal. Includes advanced features like two's complement, bit width, and programming prefixes.
Features
- Convert 4 bases at onceBinary, octal, decimal, and hex displayed simultaneously.
- Negative numbers supportCorrectly convert negative numbers using two's complement.
- Bit width selectionSpecify 8/16/32/64 bits to match programming data types.
- Programmer-friendly displayPrefix (0b, 0o, 0x) and 4-digit separator options.
Use Cases
- Number conversion in programming
- CSS color code verification
- Bit operations and two's complement
- Unix file permission checking
- Digital circuits and embedded development
FAQ
Can I use uppercase or lowercase for hex A-F?
Yes, both work correctly. Output is displayed in uppercase.
What is two's complement?
A method computers use to represent negative numbers. Enable signed mode to display negatives in two's complement format.
Why specify bit width?
To match programming data types like 8/16/32/64 bit integers.
What are prefixes?
Notation used in programming languages: 0b (binary), 0o (octal), 0x (hexadecimal).