Roman numeral converter
Numbers to Roman numerals and back, up to 3,999,999.
Number → Roman
Roman → Number
The seven symbols
| Symbol | Value |
|---|---|
| I | 1 |
| V | 5 |
| X | 10 |
| L | 50 |
| C | 100 |
| D | 500 |
| M | 1,000 |
Common years
| Year | Roman |
|---|---|
| 1000 | M |
| 1500 | MD |
| 1776 | MDCCLXXVI |
| 1900 | MCM |
| 1969 | MCMLXIX |
| 1984 | MCMLXXXIV |
| 2000 | MM |
| 2026 | MMXXVI |
How it works
Roman numerals are additive, read left to right, with one twist: a smaller symbol placed before a larger one is subtracted instead of added. That is why 4 is IV (5 − 1) rather than IIII, and 9 is IX rather than VIIII.
The subtractive rules
- Only I, X and C are ever subtracted — never V, L or D.
- I subtracts only from V and X; X only from L and C; C only from D and M.
- No symbol repeats more than three times in a row.
Those rules make the notation unambiguous, which is why this tool validates by converting your input back to a number and then to a numeral again: if the two do not match, the numeral is malformed.
Numbers above 3,999
Classical Roman numerals stop at MMMCMXCIX (3,999) because you would need four Ms for 4,000. The standard extension is the vinculum: an overline multiplies a numeral by a thousand, so V̅ is 5,000. This tool uses combining overlines so the result copies as real text.
Clock faces
Watch dials traditionally show IIII rather than IV, for visual balance against the VIII opposite. It is a stylistic convention, not a numbering system, so it is not accepted here.