Free Roman Numeral Converter
How it works
Type a number between 1 and 3999 to see its Roman numeral, or type a Roman numeral to decode it back into a number. Both directions convert live as you type, and invalid numerals like IIII or VX are rejected with a clear message.
Roman Numeral Converter
Numbers to Roman numerals and back — live, with strict validation of proper numeral form.
1 Number to Roman numeral
2 Roman numeral to number
3 Result
🏛️ Conversion
Everyday uses
- Dates and years: convert a year like 2026 (MMXXVI) for tattoos, cornerstones, wedding designs, and memorial plaques.
- Reading clocks and chapters: decode numerals on clock faces, book chapters, outlines, and movie sequel titles.
- Schoolwork: check homework answers instantly instead of counting symbols by hand.
- Events and editions: Super Bowls, Olympics, and monarch names all use Roman numerals — decode them in seconds.
Roman numeral symbols
| Symbol | Value |
|---|---|
| I | 1 |
| V | 5 |
| X | 10 |
| L | 50 |
| C | 100 |
| D | 500 |
| M | 1000 |
Frequently asked questions
Why does the converter stop at 3999? Standard Roman numerals have no symbol larger than M (1000) and allow at most three in a row, so MMMCMXCIX (3999) is the largest standard form. Bigger numbers historically used a bar over the numeral.
Why is IIII rejected if some clocks show it? IIII is a traditional clockmaker’s exception, but the standard rule allows at most three repeats — 4 is written IV. This converter follows the standard form used in publishing and exams.
Is there a Roman numeral for zero? No. The Roman system had no zero, which is one reason it was eventually replaced by Arabic numerals for mathematics.