Roman Numeral Converter
Convert numbers to Roman numerals and back, supporting 1–3999 with strict validation of non-canonical forms. Everything runs in your browser.
FAQ
What range is supported?
1 through 3999, the range expressible in standard Roman numerals.
Is a form like IIII accepted?
No. Only canonical forms (IV) validate; non-canonical inputs are rejected with an error.
Can I convert several values at once?
Yes. Enter one value per line and each line is converted.
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