How Roman numerals work
Roman numerals write numbers with seven letters: I, V, X, L, C, D and M. Values are added from left to right, so VIII is 5 + 3 = 8. When a smaller symbol comes before a larger one, it is subtracted, so IV is 5 - 1 = 4 and IX is 10 - 1 = 9. Only six such pairs are used: IV, IX, XL, XC, CD and CM.
A symbol can be repeated up to three times in a row, so III is 3 but 4 is IV, not IIII. The standard system has no zero, and the largest number that can be written with these rules is 3999, which is MMMCMXCIX.
How to use the converter
- Type a number from 1 to 3999, or a Roman numeral such as MCMXCIV.
- Read the converted value and the table that shows how it is built.
- To convert a date, pick it in the date box and copy the Roman numeral version.
- Use the chart for the numerals 1 to 20.
Rules for writing Roman numerals
- Write from the largest value to the smallest, left to right.
- Use subtraction only for IV, IX, XL, XC, CD and CM.
- Never repeat a symbol more than three times in a row.
- Never repeat V, L or D, which are written only once in a group.
- Only I, X and C can be subtracted, and only from the next two larger symbols.
Where Roman numerals are still used
You see Roman numerals on clock faces, in the names of kings, queens and popes such as Elizabeth II, in book chapters and outlines, in the numbering of sporting events like the Super Bowl, in film and TV copyright years and on buildings and monuments. They are also popular for tattoos, wedding dates and anniversaries, which is why the converter includes a date mode.
Roman numerals for years and dates
A year is written like any other number, so 2026 is MMXXVI. Dates are often written with the day, month and year as three numerals separated by dots or dashes, so 31 October 2026 becomes XXXI.X.MMXXVI. Years above 3999 cannot be shown in standard Roman numerals.
Example: building 1994
To write 1994, split it into thousands, hundreds, tens and units: 1000 + 900 + 90 + 4. In Roman numerals 1000 is M, 900 is CM, 90 is XC and 4 is IV, so 1994 is MCMXCIV. The breakdown table in the tool shows each piece so you can follow the logic. Reading it back, M is 1000, CM is 1000 minus 100 added to 1000, and so on, which is a good way to learn the subtraction rule.
Roman numeral symbols
| Symbol | Value |
|---|---|
| I | 1 |
| V | 5 |
| X | 10 |
| L | 50 |
| C | 100 |
| D | 500 |
| M | 1000 |
Frequently Asked Questions
What is 2026 in Roman numerals?
MMXXVI.
How do I write 4 in Roman numerals?
IV, which means one before five.
What is the largest Roman numeral?
In the standard system it is MMMCMXCIX, which is 3999.
Is there a Roman numeral for zero?
No. The Romans had no symbol for zero.
Why is 4 not written as IIII?
Standard rules allow at most three repeated symbols and use subtraction instead, although IIII appears on some clocks.
How do I convert Roman numerals to numbers?
Type the numeral into the converter and read the number, or add the values and subtract where a smaller symbol comes first.
Is anything uploaded?
No. Conversion happens in your browser.