Tools › Roman Numeral Converter
Roman Numeral Converter
Free online Roman numeral converter. Turn numbers into Roman numerals (1–3999) or decode MCMXCIV back to a number, with strict validation.
Use it from code
The same function is available as an API endpoint. Free tier: 200 calls per day without a key. Pro lifts the limit.
curl -X POST https://spincrus.uz/api/v1/tools/roman-numeral-converter \
-H "content-type: application/json" \
-H "x-api-key: YOUR_KEY" \
-d '{"value":"1994"}'FAQ
How do I convert a number to a Roman numeral?
Break the number into thousands, hundreds, tens and ones, and write each part with the symbols M, D, C, L, X, V, I. 1994 is M (1000) + CM (900) + XC (90) + IV (4) = MCMXCIV.
What is the largest number I can write?
This tool covers 1 to 3999 (MMMCMXCIX). Standard Roman numerals have no zero and no symbol above M; larger values were written with an overline, which plain text cannot show.
Why is my Roman numeral rejected as invalid?
Only the standard subtractive forms are accepted: IV, IX, XL, XC, CD, CM. Forms such as IIII, VX or IC are not canonical, so the tool refuses them instead of guessing a value.
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