Roman Numeral Converter
Convert numbers to Roman numerals and Roman numerals back to numbers.
Number to Roman numerals
Roman numerals to number
Roman numerals have no zero and no standard form above 3999, so this converter works with whole numbers from 1 to 3999. Only standard (canonical) forms are accepted — IIII, VV and IL are rejected, because the correct forms are IV, V and XLIX.
Roman numeral reference chart
| Symbol | Value | Symbol | Value |
|---|---|---|---|
| I | 1 | C | 100 |
| V | 5 | D | 500 |
| X | 10 | M | 1000 |
| L | 50 | — | — |
| Number | Roman numeral | Number | Roman numeral |
|---|---|---|---|
| 1 | I | 40 | XL |
| 4 | IV | 50 | L |
| 5 | V | 90 | XC |
| 9 | IX | 100 | C |
| 10 | X | 400 | CD |
| 14 | XIV | 500 | D |
| 19 | XIX | 900 | CM |
| 58 | LVIII | 1000 | M |
| 1994 | MCMXCIV | 2026 | MMXXVI |
The subtraction rule is the key: a smaller symbol before a larger one subtracts (IV = 4, IX = 9, XL = 40, XC = 90, CD = 400, CM = 900). I, X, C and M may repeat up to three times; V, L and D are never repeated.
What is a Roman numeral converter?
A Roman numeral converter translates between ordinary numbers and Roman numerals — the number system of ancient Rome, still used today on clock faces, book chapters, film credits and Super Bowl numbers. Enter a number from 1 to 3999 to see its Roman form, or enter Roman numerals to get the ordinary number back.
Roman numerals are built from seven letters: I (1), V (5), X (10), L (50), C (100), D (500) and M (1000). Symbols are normally added together (VIII = 8, LX = 60), but a smaller symbol placed before a larger one subtracts instead — IV is 4, not 6, and XC is 90, not 110. That subtraction rule is what makes forms like IIII and IL wrong: the standard writes 4 as IV and 49 as XLIX.
This converter is strict on purpose: it only accepts standard, canonical Roman numerals, so a typo such as VV or IIII is flagged rather than silently misread. Everything runs in your browser — nothing you type is sent anywhere.
How Roman numerals work
Seven letters, added together — with subtraction for 4s and 9s. I = 1, V = 5, X = 10, L = 50, C = 100, D = 500, M = 1000. Letters are added left to right (VIII = 8), except when a smaller letter comes before a bigger one, when it subtracts (IV = 4, IX = 9, XL = 40, XC = 90, CD = 400, CM = 900). So 2026 is MMXXVI and 1994 is MCMXCIV.
The converter checks your input strictly: IIII, VV and IL are not valid Roman numerals and are rejected, because the subtractive rule only allows one smaller numeral before a larger one, and only I, X and C can subtract.
Converting numbers for a maths problem? The fraction calculator and scientific calculator are here too.
How to use the Roman numeral converter
- To convert a number, enter a whole number from 1 to 3999 and press Convert to Roman numerals.
- To convert Roman numerals, type the numeral (for example MMXXVI) and press Convert to number.
- If you see an error, check for invalid letters or a non-standard form — use IV instead of IIII, IX instead of VIIII, and XL instead of XXXX.
- Use the reference chart above to check the seven symbols and common values by hand.
Frequently asked questions
What is 2026 in Roman numerals?
2026 is MMXXVI: M (1000) + M (1000) + X (10) + X (10) + V (5) + I (1) = 2026.
Why is 4 written as IV and not IIII?
Roman numerals use the subtraction rule: a smaller symbol before a larger one subtracts, so IV means 5 − 1 = 4. Writing IIII is not the standard form, and this converter rejects it.
What is the largest number this converter handles?
3999 (MMMCMXCIX). Roman numerals have no zero and no standard symbol above 1000, so numbers above 3999 need extra notation such as a bar over a symbol, which this converter does not support.
Can Roman numerals represent zero?
No. The Roman system has no symbol for zero — it was developed before zero was used as a number in Europe. The smallest value this converter accepts is 1 (I).
Why was my Roman numeral rejected?
Either it contains a letter other than I, V, X, L, C, D or M, or it is a non-standard form such as IIII, VV, IL or XXXX. The correct forms are IV, V, XLIX and XL.
Where are Roman numerals still used today?
On clock faces, in book and film chapter numbers, for monarchs and popes (Elizabeth II, Henry VIII), at the Super Bowl, and in copyright years on films — for example MCMXCIV for 1994.
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