How to use the Roman Numeral Converter
- Type a number (like 2026) or a Roman numeral (like MMXXVI).
- The converter detects which one you typed and shows the other.
- Check the breakdown to see how it's built.
What does this tool do?
Roman numerals use seven letters: I (1), V (5), X (10), L (50), C (100), D (500) and M (1,000). A smaller numeral before a larger one is subtracted (IV = 4, XC = 90); otherwise values add up.
The converter only accepts standard forms, so it will tell you that IIII or IC aren't valid, and suggest the correct form.
Why use it?
- Read dates on buildings, film credits and clocks.
- Write chapter numbers, outlines and tattoos correctly.
- Check homework.
Examples
Some numbers you'll see often:
| Number | Roman numeral |
|---|---|
| 4 | IV |
| 9 | IX |
| 14 | XIV |
| 40 | XL |
| 90 | XC |
| 400 | CD |
| 1999 | MCMXCIX |
| 2026 | MMXXVI |
Privacy
The calculation happens instantly in your browser. The numbers you enter are not sent to our servers or saved. There's no account to create and nothing to install.
Frequently asked questions
Why do clocks show IIII instead of IV?
It's a long-standing clockmaking tradition, possibly for visual balance with VIII on the other side. In standard notation, 4 is IV.
Last reviewed by the M2Toolkit team.