About the Number Base Converter
This number base converter takes a number in any of binary, octal, decimal or hexadecimal and instantly shows its equivalent in all four bases at once, rather than making you run separate conversions each way. It's built for programmers checking a byte value, students working through a computer science course, or anyone converting a color code or memory address between bases.
How to use the Number Base Converter
- 1
Type the number you want to convert.
- 2
Choose which base it's currently written in — binary, octal, decimal or hexadecimal.
- 3
Read the equivalent value in all four bases at once.
What people use it for
Checking a hex color or byte value
Convert a hexadecimal value like FF to decimal (255) to understand exactly what a color channel or byte setting represents.
Working through computer science coursework
Verify manual binary-to-decimal or decimal-to-hex conversions while learning number systems, without reaching for a scientific calculator.
Debugging low-level code
Quickly translate a binary flag or octal file permission value (like chmod's 755) into decimal or hex for a debugger or log message.
How positional number systems work
Every number system here is positional: each digit's value depends on its position, multiplied by a power of the base. In decimal (base 10), the digits in '255' represent 2×100 + 5×10 + 5×1. Binary (base 2) uses only 0 and 1, with each position worth a power of two; hexadecimal (base 16) uses 0-9 then A-F to represent 10-15 in a single digit, which is why FF equals 255 — each F is 15, and 15×16 + 15 = 255.
Tips
- Hexadecimal is shown uppercase by convention, but lowercase hex is equally valid — most programming languages accept either.
- The largest value this tool converts precisely is 9,007,199,254,740,991, the largest integer JavaScript can represent exactly without rounding.
- Octal (base 8) is less common today but still shows up in Unix file permissions, where each digit represents read/write/execute bits.