NumbersHow to use the converter
Type figures to get a Roman numeral, or letters to get a number. The result shows the numeral, the number in words and how the numeral is built from its parts, so that you can check your own working. It accepts only correctly formed numerals. If you type IIII or IC, it tells you so and does not guess, because a school answer in that form would be marked wrong.
The symbols at a glance
| I | V | X | L | C | D | M |
|---|---|---|---|---|---|---|
| 1 | 5 | 10 | 50 | 100 | 500 | 1000 |
Letters are added when a smaller one follows a larger one (VI is 6) and subtracted when a smaller one comes first (IV is 4). Only six subtractive pairs are allowed: IV, IX, XL, XC, CD and CM.
Why it stops at 3999
No letter may be written more than three times in a row, and there is no single letter above M. So the largest numeral in the standard form is MMMCMXCIX, which is 3999. There is also no Roman numeral for zero. Larger values were written by the Romans with a bar over a letter to multiply it by a thousand, which is beyond school work.
Good uses
- Checking homework on Roman numerals.
- Reading the year at the end of a film or on a foundation stone.
- Writing chapter numbers, class numbers or a date in Roman numerals for a card or a design.
Learn more
The rules of Roman numerals with worked examples, and the chart of Roman numerals from 1 to 100. What you type stays in your browser.