Roman Numeral Converter
Convert numbers to Roman numerals and Roman numerals back to numbers (1–3999). Instant, two-way, and fully client-side.
Convert numbers to Roman numerals and back in both directions. Type an ordinary number from 1 to 3999 to see its Roman form, or paste a Roman numeral to get the value — useful for dates, clock faces, book chapters, movie sequels, and Super Bowl numbering.
How to use it
No account, no upload — it all happens on your device.
How Roman numerals work
Seven letters, combined by adding and subtracting.
| Symbol | Value |
|---|---|
| I | 1 |
| V | 5 |
| X | 10 |
| L | 50 |
| C | 100 |
| D | 500 |
| M | 1000 |
Symbols are written largest to smallest and added together — XVI is 10 + 5 + 1 = 16. When a smaller symbol sits before a larger one, you subtract it: IX is 10 − 1 = 9. No symbol repeats more than three times in a row, which is exactly why 4 is IV rather than IIII.
Worked examples
Common conversions in both directions.
| Number | Roman numeral |
|---|---|
| 4 | IV |
| 49 | XLIX |
| 1984 | MCMLXXXIV |
| 2025 | MMXXV |
| 3999 | MMMCMXCIX |
Where you'll still see Roman numerals
- Clocks and watches. Many dials use I–XII, often with IIII in place of IV for visual balance.
- Dates and copyright lines. Films and books stamp the year as Roman numerals, e.g. MMXXV for 2025.
- Sequels and editions. Super Bowl LIX, World War II, and chapter or volume numbers in books.
- Outlines and naming. Monarchs and popes (Elizabeth II, Benedict XVI) and the top level of formal outlines.