Number Base Converter
Convert whole numbers between binary, octal, decimal, hexadecimal, and any base up to 36, write text as binary or hex bytes and read it back, and convert numbers to and from Roman numerals.
Whole numbers of any size, with an optional minus sign. Prefixes such as 0x are fine.
Type a number and read it in every base.
On this device
No signup. Your input is never uploaded.
How to use the Number Base Converter
Choose Number bases, Text and bytes, or Roman numerals.
For numbers, type the number and choose the base it is written in.
For text, choose Text to bytes or Bytes to text, and the base to use.
Copy the result you need.
Questions about the Number Base Converter
Choose Number bases, set From base to Binary, and type the binary number. The decimal value appears beside binary, octal, and hexadecimal, and you can pick one more base to show.
Yes. Numbers are worked out exactly, however large, up to 10,000 digits, so there is no rounding as with ordinary calculator numbers.
Text is written as the bytes it is stored as, using UTF-8. A basic letter such as A is one byte, 01000001 in binary or 41 in hex, and a symbol such as the euro sign is three bytes.
Whole numbers from 1 to 3999 in the standard form. Forms that are not standard, such as IIII, are rejected instead of guessed at.