Number Converter | Decimal, Binary, Octal, Hexadecimal
Free online number system converter. Convert between decimal, binary, octal, and hexadecimal numbers instantly. Perfect for programming, math, and computer science.
Free Online Number System Converter
Our number converter tool allows you to instantly convert between different number systems. Whether you're a programmer converting decimal to binary, a student learning hexadecimal, or working with octal numbers, our tool provides accurate conversions in real-time.
Supported Number Systems
Decimal (Base 10)
- Digits: 0-9
- Symbol: DEC
- Common Use: Everyday mathematics
Binary (Base 2)
- Digits: 0-1
- Symbol: BIN
- Common Use: Computer systems
Octal (Base 8)
- Digits: 0-7
- Symbol: OCT
- Common Use: Unix permissions
Hexadecimal (Base 16)
- Digits: 0-9, A-F
- Symbol: HEX
- Common Use: Web colors, memory addresses
How to Use the Number Converter
- Enter the number - Type the number you want to convert in the "Convert From" field
- Select "From" system - Choose the number system you're converting from (e.g., Decimal)
- Select "To" system - Choose the number system you want to convert to (e.g., Binary)
- Get instant results - The converted number appears automatically
- Use quick values - Click on common values like "10 (DEC)" or "FF (HEX)" for quick conversion
Common Number Conversion Examples
| Conversion | Input | Output |
|---|---|---|
| Decimal to Binary | 10 (DEC) | 1010 (BIN) |
| Binary to Decimal | 1101 (BIN) | 13 (DEC) |
| Decimal to Hexadecimal | 255 (DEC) | FF (HEX) |
| Hexadecimal to Decimal | A5 (HEX) | 165 (DEC) |
| Binary to Hexadecimal | 11001100 (BIN) | CC (HEX) |
Practical Applications
💻 Programming & Computer Science
Convert between number systems for low-level programming, memory addressing, and digital electronics.
🎨 Web Design & Development
Convert color values between decimal RGB and hexadecimal color codes for CSS and design work.
📚 Mathematics & Education
Students can explore different number bases and understand positional numeral systems.
🔧 System Administration
Convert Unix file permissions between octal notation and binary representation.
Number System Fundamentals
What is a Number System?
A number system is a way to represent numbers using digits or symbols. The base (or radix) determines how many distinct digits are used. Our converter supports these four common bases:
Decimal (Base 10)
- Uses digits 0-9
- Most familiar system
- Used in everyday life
- Positional value increases by powers of 10
Binary (Base 2)
- Uses digits 0 and 1
- Foundation of digital systems
- Used by computers internally
- Positional value increases by powers of 2
Octal (Base 8)
- Uses digits 0-7
- Compact representation of binary
- Used in Unix file permissions
- Positional value increases by powers of 8
Hexadecimal (Base 16)
- Uses digits 0-9 and A-F
- Very compact representation
- Used for memory addresses, colors
- Positional value increases by powers of 16
💡 Conversion Tips
Quick Conversions
- Decimal to Binary: Divide by 2 repeatedly, collect remainders
- Binary to Decimal: Multiply each digit by 2position
- Hex to Binary: Convert each hex digit to 4 binary digits
- Binary to Hex: Group binary digits in 4s, convert each group
Remember These Common Values
Start Converting Now!
Try our number converter with these common conversions: