Number Base Converter
Convert numbers between binary, octal, decimal, hexadecimal, and any base (2-36)
What is the Number Base Converter?
Written and maintained by the BitConvert team · Feb 27, 2026
The Number Base Converter translates a whole number from one positional numeral system into every other common base at once. A base, or radix, is simply how many distinct digits a system uses: binary (base 2) uses 0-1, octal (base 8) uses 0-7, decimal (base 10) uses 0-9, and hexadecimal (base 16) uses 0-9 plus A-F. Beyond these four, the tool accepts any custom base from 2 to 36, using letters A-Z for digit values above nine.
Enter a value, pick the base it is written in, and the converter parses it to an integer and re-expresses that same quantity in the other bases instantly. Because one hex digit maps exactly to four binary digits, hexadecimal stays popular for compactly writing memory addresses, byte values, and color codes. Everything runs in your browser, so conversions are immediate and offline-friendly.
Key Features
All Common Bases
Convert simultaneously between binary, octal, decimal, and hexadecimal without switching modes or re-entering the number.
Custom Radix 2-36
Work in any base from 2 to 36, using digits 0-9 and letters A-Z for values ten and above.
Instant Multi-Output
A single input is displayed in every base at once, so you never have to run conversions one direction at a time.
Input Validation
The tool checks that each digit is legal for the selected base, flagging characters that fall outside that radix's range.
Common Use Cases
Read and write hexadecimal memory addresses, opcodes, or register values while debugging low-level code. Translate a CSS or design hex color like FF5733 into its decimal RGB components. Check bitmask and flag values by viewing a decimal number in binary. Help students verify positional-notation homework by comparing binary, octal, and hex against decimal. Decode octal file permissions or fixed-width binary fields from a protocol spec.
Frequently Asked Questions
Last updated: Feb 27, 2026