Roman Numeral Converter
Type an integer to get its Roman numeral form, or type Roman numerals to get the number back — with validation either way.
Three steps, no setup
Type a number or numeral
The tool detects which direction you are converting automatically.
See the converted value
Standard subtractive notation (like IV for 4) is applied correctly.
Check for invalid input
Malformed numerals are flagged instead of silently guessed.
Frequently asked questions
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