Roman Numerals

Convert numbers to and from Roman numerals (1–3999).

Convert


Sponsored

How it works

How it works

  • Number → Roman: greedy subtraction using pairs like CM (900), CD (400), XC (90), XL (40), IX (9), IV (4).
  • Roman → Number: scan from right to left; subtract when a smaller symbol precedes a larger one.
  • Validation uses a regex for standard forms up to 3999 (no overlines for 5000+).

Privacy & Security

All local.

Accuracy, Limits & Tips

Supports only standard forms up to 3999.

Examples

  • 1999 → MCMXCIX
  • MMXXV → 2025

Looking for broader guides and best practices? Visit the ToolsAreUs Blog for indexes (like the full tool list) and articles (e.g. secure password generation).