Converters
Roman Numeral Converter
Convert whole numbers to ordinary Roman numerals and reject noncanonical Roman spellings on the reverse path.
About this tool
When to use it
Convert whole numbers to ordinary Roman numerals and reject noncanonical Roman spellings on the reverse path.
How to use it
Choose Integer to Roman or Roman to integer, enter the corresponding value, and select Convert numeral. Replace the input when changing direction; the existing text is not automatically translated by the mode switch.
Guide updated . Examples checked against this implementation.
Worked examples
A subtractive form
Input
Integer to Roman: 1994Expected output
MCMXCIVM is 1000, CM is 900, XC is 90, and IV is 4. Reverse conversion returns 1994.
Errors and unsupported input
IIIIUse IV. The reverse converter requires standard canonical subtraction and repetition rules.
Continue this workflow
- Integer Base Converter: Convert positional numeral systems such as binary or hexadecimal.
Questions
Frequently asked questions
Why is a historical clock-face numeral rejected?
Clock faces sometimes use IIII. This converter intentionally checks canonical arithmetic notation, so it expects IV.