Math

Roman Numeral Converter

Convert any number to Roman numerals or decode Roman numerals back to Arabic numbers — with a clear step-by-step breakdown.

🔁 Two-way conversion

Go from digits to numerals and back with full validation.

✓ Input validation

Invalid numeral sequences like "IIII" are caught and explained.

📚 Reference table

Key symbols from I to M with their Arabic values.

📅 Year-friendly

Perfect for translating years, Super Bowls and movie titles.

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Numbers, converted and simplified.