Roman Numeral Calculator
Convert integers to Roman numerals and Roman numerals to integers (range 1–3999). See a step-by-step breakdown of each conversion.
About Roman Numerals
Roman numerals use seven symbols: I (1), V (5), X (10), L (50), C (100), D (500), and M (1000). Subtractive notation allows IV (4), IX (9), XL (40), XC (90), CD (400), and CM (900). The system covers 1–3999 (MMMCMXCIX). Numbers larger than 3999 traditionally used a bar (vinculum) notation. The conversion algorithm iterates through values from largest to smallest, subtracting greedily — similar to how a greedy algorithm works in our Big Number Calculator.
Roman numerals were standard across the Roman Empire and remained in use through the Middle Ages. Today they appear on clock faces, copyright years, Super Bowl numbering, and movie credits. To decode a number like MMXXIV: M=1000, M=1000, X=10, X=10, I=1 before V means -1, V=5 → total = 2000+20+4 = 2024. For binary and hexadecimal number base conversions, try the Binary Calculator.
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