Roman Numeral Converter
Convert a number to Roman numerals, or a Roman numeral back to a number — both directions, live, in your browser.
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Runs in your browser. Your input is not uploaded to PayloadIQ.
Uses standard subtractive notation — 4 is IV (not IIII), 9 is IX, 90 is XC — across the representable range of 1 to 3999.
The decoder is strict: it only accepts well-formed numerals and rejects malformed ones like IIII, VV or IC, so you can trust the result. Everything runs locally.