How to Use the Roman Numeral Converter
Type a number (1–3,999) in the left box to get the Roman numeral, or type a Roman numeral like XIV in the right box to get the number. The result updates as you type, with a step-by-step breakdown underneath.
Roman Numerals Chart
| Number | Roman numeral |
|---|---|
| 1 | I |
| 4 | IV |
| 5 | V |
| 9 | IX |
| 10 | X |
| 40 | XL |
| 50 | L |
| 90 | XC |
| 100 | C |
| 400 | CD |
| 500 | D |
| 900 | CM |
| 1,000 | M |
Roman Numerals 1 to 20
1 = I, 2 = II, 3 = III, 4 = IV, 5 = V, 6 = VI, 7 = VII, 8 = VIII, 9 = IX, 10 = X, 11 = XI, 12 = XII, 13 = XIII, 14 = XIV, 15 = XV, 16 = XVI, 17 = XVII, 18 = XVIII, 19 = XIX, 20 = XX.
The Rules of Roman Numerals
- Add when equal or smaller follows larger: VI = 5 + 1 = 6, XX = 20.
- Subtract when smaller comes first: IV = 5 − 1 = 4, IX = 9, XL = 40, XC = 90, CD = 400, CM = 900.
- Only I, X and C are subtracted, and only from the next two larger symbols (I from V/X, X from L/C, C from D/M).
- No symbol repeats more than three times in a row: 4 is IV, not IIII.
- V, L and D never repeat.
Why is the limit 3,999? Standard Roman numerals have no symbol above M (1,000), and M can only repeat three times. Larger numbers historically used a bar over a numeral to multiply it by 1,000.
Converting Years to Roman Numerals
Roman numerals are popular for years in movie credits, building cornerstones, tattoos and anniversaries. For example, 2026 = MMXXVI, 2000 = MM, 1999 = MCMXCIX and 1990 = MCMXC. Enter any year above to convert it with the full breakdown.
Works on Every Device
The Roman Numeral Converter works in any browser on desktop, tablet or phone, and keeps working offline once the page has loaded. Results appear as you type, so there's no button to press, and you can copy the answer with one click. Bookmark this page to have it ready next time.
Troubleshooting & Tips
- "Not a valid Roman numeral" error Check the rules: no more than three repeats (IIII is invalid), and only valid subtractive pairs like IV, IX, XL, XC, CD and CM.
- Can I enter lowercase? Yes. Lowercase numerals such as xiv are converted automatically.
- Numbers above 3,999 Standard Roman numerals stop at 3,999 (MMMCMXCIX). Larger values historically used a bar over the numeral.
- Decimals or zero Roman numerals have no zero and no decimals, so enter whole numbers from 1 upward.
Frequently Asked Questions
How do you write 2026 in Roman numerals?
2026 in Roman numerals is MMXXVI (MM = 2000, XX = 20, VI = 6).
What is 4 in Roman numerals?
4 is IV, which means one less than five. IIII is not standard.
What is the largest Roman numeral?
With standard symbols, the largest number is 3,999, written MMMCMXCIX.
Is there a zero in Roman numerals?
No. The Roman numeral system has no symbol for zero.
How do I convert Roman numerals to numbers?
Type the numeral in the right-hand box. Add each symbol's value, and subtract when a smaller symbol comes before a larger one.
Written by Prakhar Singh, software engineer and creator of K4Converter · Last updated October 2026