Number Converter
Bases 2 to 36, text to binary or hex, Roman numerals, and numbers written out in words in English, French, German and Spanish, cheque amounts included.
Everything is calculated in your browser: your numbers and texts are never sent anywhere.
About this tool
This number converter combines four tools. The first converts a whole number between bases (binary, octal, decimal, hexadecimal or any base from 2 to 36), with exact arithmetic even for numbers hundreds of digits long, plus the number of bits and bytes and the two’s complement of negative values. The second turns text into binary, hexadecimal, decimal (ASCII codes) or Unicode code points, and rebuilds the text from those UTF-8 bytes. The third converts Roman numerals both ways, from 1 to 3,999 and up to 3,999,999 with the overline.
The fourth writes a number or a euro amount out in words, in English, French, German or Spanish: handy for writing a cheque, drafting a contract or checking tricky forms such as French “quatre-vingts”. In English you can keep or drop the British “and” after hundred; in French you choose the traditional or the 1990 spelling and the variant used in France, Belgium or Switzerland. Every result copies in one click, and input works in any field: type binary, hex or Roman numerals and the conversion runs the other way.
- Bases 2 to 36 with exact big integers
- Text to binary, hex, decimal and Unicode, and back
- Roman numerals from 1 to 3,999,999 with overline
- Numbers and euro amounts in words
- English, French, German and Spanish
- French 1990 spelling, Belgian and Swiss variants
How to use it
- Choose the Bases, Text, Roman numerals or Numbers in words tab.
- Type your value in any field: the others update straight away.
- Adjust the options (grouping, separator, overline, language, variant).
- Click the copy icon next to the result you need.