Number Base Converter
Free online number base converter. Instantly convert binary to decimal, decimal to binary, hex to decimal and 15 more base combinations. Perfect for programming, engineering and computer science.
About this tool
Convert binary to decimal, decimal to binary, hex to decimal and any other base pair from 2 to 20 instantly. Maximum precision, zero delays.
Technical Notes
Key technical details about the bases supported by this converter:
- Binary (Base 2)Uses only 0 and 1 — the foundation of all digital computing and hardware logic.
- Octal & HexadecimalCompact representations used in memory addressing, file permissions, and color codes.
- Decimal (Base 10)The standard human-readable system used as the primary interface for all conversions.
- Advanced BasesSupport for bases 11–20, including vigesimal (base 20) used by ancient civilizations.
Common Applications
Number base conversion is a fundamental skill in computer science and engineering. Common real-world uses include:
- Software DebuggingDebug binary and hexadecimal representations in embedded systems and low-level programming.
- Educational PracticePractice numeral system conversions for computer science and digital electronics coursework.
- Systems ProgrammingConvert memory addresses between octal, decimal and hexadecimal in assembly programming.
- Historical ResearchExplore historical numeral systems such as vigesimal for academic and mathematical research.
How to use
Enter Number
Type or paste the number you want to convert in the 'Number' field.
Select Bases
Choose the source base (From) and the target base (To) from the dropdown menus.
Copy Result
The converted number will appear instantly in the result area for you to copy.
Conversion Reference Table
The same numbers expressed in binary, octal, decimal and hexadecimal — the four most common bases in computing.
| Decimal (10) | Binary (2) | Octal (8) | Hexadecimal (16) |
|---|---|---|---|
| 1 | 1 | 1 | 1 |
| 8 | 1000 | 10 | 8 |
| 10 | 1010 | 12 | A |
| 16 | 10000 | 20 | 10 |
| 42 | 101010 | 52 | 2A |
| 100 | 1100100 | 144 | 64 |
| 255 | 11111111 | 377 | FF |
Questions & Answers
Binary ↔ Hexadecimal. Hexadecimal is a compact representation of binary: each hex digit maps exactly to 4 binary digits (nibble). For example, 0xFF = 11111111 in binary = 255 in decimal.
Enter the binary number in the input field, select Base 2 as the source, and Base 10 as the target. The result appears instantly — no button press needed.
Hexadecimal is used for memory addresses, color codes (#RGB), file permissions in Unix (e.g. chmod 0x755), network MAC addresses, and raw byte values in debugging tools and hex editors.
Yes. This tool supports safe integers up to 2⁵³ - 1 (about 9 quadrillion in decimal). For most practical uses in programming and education, this limit is never reached.