Roman numeral converter
Convert numbers to Roman numerals and back, live.
Common Roman numerals
| Number | Roman numeral |
|---|---|
| 1 | I |
| 2 | II |
| 3 | III |
| 4 | IV |
| 5 | V |
| 6 | VI |
| 7 | VII |
| 8 | VIII |
| 9 | IX |
| 10 | X |
| 20 | XX |
| 30 | XXX |
| 40 | XL |
| 50 | L |
| 60 | LX |
| 70 | LXX |
| 80 | LXXX |
| 90 | XC |
| 100 | C |
| 150 | CL |
| 200 | CC |
| 300 | CCC |
| 400 | CD |
| 500 | D |
| 600 | DC |
| 700 | DCC |
| 800 | DCCC |
| 900 | CM |
| 1000 | M |
| 1500 | MD |
| 1776 | MDCCLXXVI |
| 1900 | MCM |
| 1945 | MCMXLV |
| 1994 | MCMXCIV |
| 2000 | MM |
| 2024 | MMXXIV |
| 2025 | MMXXV |
| 3000 | MMM |
| 3999 | MMMCMXCIX |
- Works both directions
- Validates 1 to 3999
- Common years included
How to convert Roman numerals
- Type a number, or a Roman numeral, in either box.
- The other box updates as you type.
- Check the table for a common number or year.
How the subtraction rule works
Seven letters carry a fixed value: I is 1, V is 5, X is 10, L is 50, C is 100, D is 500 and M is 1000. Reading left to right, values normally add together, like VI for 6 (5 + 1).
A smaller numeral placed before a larger one is subtracted instead, but only in specific pairs: I before V or X (4, 9), X before L or C (40, 90), and C before D or M (400, 900). That is why 44 is XLIV (40 + 4), not XXXXIIII, and 90 is XC, not LXXXX. The same pattern repeats at each tier, just with the next pair of letters standing in for 1, 5 and 10.
| Tier | 1x | 4x (subtract) | 9x (subtract) |
|---|---|---|---|
| Units (1-9) | I | IV | IX |
| Tens (10-90) | X | XL | XC |
| Hundreds (100-900) | C | CD | CM |
Anything ending in 4 or 9 borrows the matching row here: 400 is CD, 40 is XL, and 4 is IV, all the same subtraction one tier apart.
Converting 2026 step by step
The tool builds a Roman numeral the same way by hand: repeatedly take the biggest value from the table that still fits, write its symbol, and subtract it. For 2026:
- 2026 is at least 1000, so write M and subtract it: 1026 left.
- 1026 is still at least 1000, so write another M: 26 left.
- 26 is less than 900, 500, 400, 100 and 90, but at least 10: write X and subtract it: 16 left.
- 16 is at least 10 again: write another X: 6 left.
- 6 is less than 9 but at least 5: write V and subtract it: 1 left.
- 1 is exactly I: write it, and 0 is left.
Put the symbols in the order they were written and 2026 becomes MMXXVI.
Numerals worth knowing
| Number | Roman numeral | Why it stands out |
|---|---|---|
| 14 | XIV | Combines a tens and a units subtraction |
| 58 | LVIII | Super Bowl LVIII, played February 2024 |
| 59 | LIX | Super Bowl LIX, played February 2025 |
| 1888 | MDCCCLXXXVIII | 13 letters, one of the longest years |
| 1994 | MCMXCIV | Uses all three subtraction pairs, and this calculator's own default |
| 2026 | MMXXVI | The year worked out step by step above |
| 3999 | MMMCMXCIX | The largest number this tool accepts |
Where Roman numerals still show up
- Clock and watch faces, often with IIII instead of IV at the 4 position.
- Movie sequels and copyright years in film credits.
- Outline levels and the numbered front matter (preface, introduction) of books.
- Monarch and pope regnal numbers, like Elizabeth II or Pope Francis I.
- Super Bowl numbering, and the numbering of some Olympic Games.
- Chapter and volume numbers in textbooks and legal codes, where a lower-case form like iv or ix is common.
Roman numeral converter FAQ
How do I write 1994 in Roman numerals?
1994 is MCMXCIV: M (1000) + CM (900) + XC (90) + IV (4).
Why does typing IIII show an error?
IIII is not standard Roman numeral form. Modern usage subtracts instead of repeating four times, so 4 is written IV.
Can I convert a year to Roman numerals?
Yes, type the year as a number, like 2025, and the Roman numeral box updates to MMXXV.
Why do some clocks show IIII instead of IV for 4?
Many clock and watch faces use IIII rather than IV, a centuries-old clockmaking convention. This tool follows the standard subtractive rule and always converts 4 to IV.
What Roman numeral is the current Super Bowl?
Super Bowl 58, played in February 2024, was Super Bowl LVIII. Super Bowl 59, played in February 2025, was Super Bowl LIX.
Why is 1888 written with so many letters?
1888 is MDCCCLXXXVIII, 13 characters, because 8, 8 and 8 each need the longest form (VIII, LXXX, DCCC) with no shorter subtractive shortcut available.
Can Roman numerals show zero or negative numbers?
No. The Roman system has no symbol for zero and no way to show a negative number, so this tool only accepts whole numbers from 1 to 3999.
Why does the tool stop at 3999?
M is the largest standard symbol at 1000, and repeating it more than three times in a row (MMMM) is not standard form, so 3999 (MMMCMXCIX) is the highest number the usual rules can write. Larger numbers historically used a bar over a numeral to mean times 1000, but that notation is rarely supported by fonts or keyboards today.