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Roman Numeral Converter
Type a number to get its Roman numeral, or type a Roman numeral to get the number. The converter works out which way to go on its own, handles dates like 10/14/2026, and converts a whole list at once when you put one value on each line. Every result shows how the numeral breaks down, so you can see where each letter comes from.
How to use it
- Type or paste a number, a Roman numeral, or a date into the box on the left.
- For a list, put each value on its own line. You can mix numbers, numerals, and dates.
- Choose uppercase or lowercase numerals and how date parts are separated.
- Copy or download the results. Pick Input = result if you want each original value kept next to its conversion.
The seven Roman numerals
| Numeral | Value |
|---|---|
| I | 1 |
| V | 5 |
| X | 10 |
| L | 50 |
| C | 100 |
| D | 500 |
| M | 1,000 |
Numerals are added from left to right, largest first, so VIII is 5 + 1 + 1 + 1 = 8. When a smaller numeral comes before a larger one, it's subtracted instead. Only six of these subtractive pairs are standard: IV (4), IX (9), XL (40), XC (90), CD (400), and CM (900).
Each place value is written separately. For example, 1994 is 1000 + 900 + 90 + 4, which is M + CM + XC + IV = MCMXCIV.
Dates in Roman numerals
Dates are converted one part at a time and kept in the order you typed them, so 10/14/2026 becomes X/XIV/MMXXVI. Use the Date separator option to switch to dots, dashes, spaces, or bullets, like X • XIV • MMXXVI, a common style for tattoos and engravings. Roman numeral dates work in reverse too, so X.XIV.MMXXVI converts back to 10.14.2026.
Numbers above 3,999
With standard numerals, the largest number you can write is 3,999 (MMMCMXCIX), since no symbol is repeated more than three times in a row. For bigger numbers, a bar over a numeral, called a vinculum, multiplies it by 1,000. So 5,000 is V̅, and 12,500 is X̅I̅I̅D. Turn off Overline above 3,999 if you only want standard numerals.
Non-standard numerals
Forms like IIII for 4 or IC for 99 still get converted, but the tool flags them and shows the standard version. IIII is common on clock faces, but most style guides and references use IV.
Frequently asked questions
Is there a Roman numeral for zero?
No. The Roman system had no symbol for zero and no way to write negative numbers or fractions in this notation, so the converter only accepts whole numbers from 1 up.
Why is 2026 written as MMXXVI?
2026 is 2000 + 20 + 6. That's MM for 2000, XX for 20, and VI for 6, written together as MMXXVI.
Can I convert lowercase Roman numerals?
Yes. Input can be uppercase or lowercase, like xiv or XIV. The tool also reads Unicode Roman numeral characters such as Ⅻ, and numerals with a macron or overline.
How do I convert a list of years?
Paste the years with one on each line. Every line is converted separately, and Copy or Download gives you the results in the same order, with a blank line wherever an entry couldn't be read.
Is my input sent anywhere?
No. All conversion happens in your browser, and nothing you type leaves your device.