Number Base Converter
Convert numbers between binary, octal, decimal, and hexadecimal instantly.
How to use Number Base Converter
- Choose which base your number is currently in.
- Type the number — all four bases update instantly.
- Use the copy button next to any result to copy it.
About this tool
The Number Base Converter converts a number between binary (base 2), octal (base 8), decimal (base 10), and hexadecimal (base 16) all at once — enter it in any one base and see it in all four. Uses arbitrary-precision integer arithmetic, so it stays exact even for numbers far larger than what normal 64-bit calculators can represent precisely. All conversion runs instantly in your browser — nothing is uploaded or sent to a server.
Frequently Asked Questions
Can I enter negative numbers?
Yes — start the number with a minus sign. The converter handles negative values the same way across all four bases.
Is there a size limit on the number?
No practical one — this uses arbitrary-precision integer arithmetic (not standard floating-point numbers), so very large values stay exact instead of losing precision the way a typical calculator would beyond about 15-17 significant digits.
Why does hexadecimal show letters?
Hexadecimal (base 16) needs 16 distinct digits, so after 0-9 it continues with A-F to represent values 10 through 15 — this is a standard convention, not specific to this tool.