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Roman Numeral Converter

Math & Logic

Convert between decimal numbers (1–3999) and Roman numerals with validation and subtractive notation support.

Result will appear here...
📖 Usage Guide

Roman Numeral Reference

I = 1 V = 5 X = 10 L = 50 C = 100 D = 500 M = 1000

Subtractive Rules

  • IV = 4, IX = 9
  • XL = 40, XC = 90
  • CD = 400, CM = 900
2024 → MMXXIV 1999 → MCMXCIX XLII → 42