| Roman part | Value |
|---|
| Roman numeral | Value | Use |
|---|---|---|
| I | 1 | One |
| IV | 4 | One before five |
| V | 5 | Five |
| IX | 9 | One before ten |
| X | 10 | Ten |
| XL | 40 | Ten before fifty |
| L | 50 | Fifty |
| XC | 90 | Ten before one hundred |
| C | 100 | One hundred |
| CD | 400 | One hundred before five hundred |
| D | 500 | Five hundred |
| CM | 900 | One hundred before one thousand |
| M | 1,000 | One thousand |
Convert an Arabic whole number to its standard Roman numeral form. The breakdown shows how thousands, hundreds, tens, and ones combine.
The converter uses modern canonical notation, including subtractive forms such as IV for 4 and CM for 900. Plain-text Roman numerals above 3999 are not included because they require inconsistent overline conventions.
The symbols I, X, C, and M may repeat where standard notation permits. IV, IX, XL, XC, CD, and CM use subtraction. Noncanonical forms such as IIII, VX, or IC are rejected instead of being silently interpreted.
Date mode converts the day, month, and year separately and supports three display orders. It is useful for decorative dates, inscriptions, chapter headings, clocks, and historical references. Standard notation on this page is limited to years through 3999 because larger values require overline conventions that are not represented consistently in plain text.
Related conversions: Roman Numeral Converter · Roman Numerals to Numbers · Numbers to Roman Numerals · Date Calculator