Number Base Converter
Free online tool to convert numbers between any two bases from 2 to 20. Convert binary to decimal, hexadecimal to octal, or any combination instantly with maximum precision and zero delays.
How Number Base Conversion Works
This tool parses the input number in its source base and converts it to the target base using mathematically exact algorithms. The conversion runs entirely in your browser, ensuring privacy and speed for integers within the standard safe numerical range (up to 2⁵³ − 1).
Common Applications
Number base conversion is a fundamental skill in computer science and engineering. Common real-world uses include:
- ✓Debug binary and hexadecimal representations in embedded systems and low-level programming
- ✓Practice numeral system conversions for computer science and digital electronics coursework
- ✓Convert memory addresses between octal, decimal and hexadecimal in systems and assembly programming
- ✓Explore historical numeral systems such as vigesimal (base 20, used by the Maya) for academic research
Technical Notes and Supported Bases
Key technical details about the bases supported by this converter:
- •Binary (base 2): uses only 0 and 1 — the foundation of all digital computing, hardware logic, and bitwise operations
- •Octal (base 8) and Hexadecimal (base 16): compact representations widely used in memory addressing, Unix file permissions, and color codes
- •Decimal (base 10): the standard human-readable system; all other bases are derived from or converted through decimal internally
- •Vigesimal (base 20): historically used by the Mayan civilization; also supported alongside bases 2–19 for academic and historical use
Frequently Asked Questions
What is the most common number base conversion in programming?
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.
How do I convert binary to 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.
What is hexadecimal used for in programming?
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.
Are there limits to the numbers I can convert?
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.