Roman Numeral Converter

About this tool

Roman numerals still turn up everywhere — clock faces, book chapters, film copyright years, Super Bowl numbers, the names of monarchs and popes, and a lot of tattoos and wedding invitations. They're easy to read once you know the rules and surprisingly easy to get wrong when you write them. This converter works in both directions, shows how each result is built, and flags numerals that aren't written in the standard form. It runs in your browser.

How to use the Roman Numeral Converter

1. Type a number between 1 and 3,999 to get its Roman numeral, or type a numeral (upper or lower case) to get its value. The direction is detected automatically.
2. Read the breakdown under the result to see which symbols make up the number.
3. For a date, pick it in the date box, choose the order (month-day-year is standard in the US, day-month-year in most other countries) and a separator, then copy the result.

The rules of Roman numerals

There are seven symbols: I = 1, V = 5, X = 10, L = 50, C = 100, D = 500 and M = 1,000. Symbols are written from largest to smallest and added together, so VIII is 5 + 1 + 1 + 1 = 8. To avoid four of the same symbol in a row, six subtractive pairs are used, where a smaller symbol placed before a larger one is subtracted:

• IV = 4 and IX = 9
• XL = 40 and XC = 90
• CD = 400 and CM = 900

Only those six pairs are standard. I can only come before V or X, X only before L or C, and C only before D or M, which is why 99 is XCIX (90 + 9) and not IC, and 49 is XLIX rather than IL. V, L and D are never repeated or subtracted. Following these rules, every number from 1 to 3,999 has exactly one correct form — the largest is MMMCMXCIX.

Worked examples

1994 splits into 1000 + 900 + 90 + 4, which is M + CM + XC + IV, giving MCMXCIV. 2026 is 2000 + 20 + 6, or MM + XX + VI, giving MMXXVI. Going the other way, MCMLXXXIV reads as M (1000) + CM (900) + LXXX (80) + IV (4) = 1984.

For a date, 27 September 2026 in US order (month, day, year) becomes IX · XXVII · MMXXVI: September is the ninth month (IX), the day is 27 (XXVII) and the year is 2026 (MMXXVI). In day-month-year order the same date is XXVII · IX · MMXXVI. Some people shorten the year to two digits, so 2026 becomes 26 (XXVI); if you do that, decide deliberately, because IX · XXVII · XXVI is easy to misread later.

Getting a date tattoo or engraving right

Most Roman-numeral mistakes in tattoos come from three things. First, the order: a date written month-first reads differently to someone who writes day-first, so pick one and keep a note of it. Second, non-standard forms such as IIII for 4 or IC for 99, which look wrong to anyone who knows the rules (IIII does appear on many clock faces by tradition, but it isn't the standard form). Third, mixing up similar-looking years: 1990 is MCMXC and 1999 is MCMXCIX. Paste the finished numeral back into the converter above — it reads it back as a number and warns you if it isn't in standard form, which is a quick way to double-check before anything permanent happens.

Common uses

• Birth, wedding or anniversary dates for tattoos, rings, invitations and plaques
• Outline numbering and front-matter page numbers (i, ii, iii) in documents
• Reading copyright years at the end of films and TV programmes
• Event numbering, such as a 50th anniversary (L) or Super Bowl LX

Limits of the system

Standard Roman numerals have no zero and no negative numbers, and they stop at 3,999. Romans wrote larger values by putting a bar over a numeral to multiply it by 1,000, but that notation isn't consistent and most fonts can't show it reliably, so this converter sticks to the standard 1–3,999 range. That covers every day, month and year you're likely to need.

Quick reference chart

Common values and their Roman numerals

Number	Numeral	Number	Numeral
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
30	XXX	40	XL
50	L	60	LX
70	LXX	80	LXXX
90	XC	100	C
200	CC	300	CCC
400	CD	500	D
900	CM	1000	M
2000	MM	3000	MMM

Roman numeral years chart, 1990 to 2029

Birth, wedding and anniversary years are the most common thing people convert. Every value below is in standard form:

Notice how the 1990s all start with MCMXC and the 2000s with MM. The longest year in this range is 1998, MCMXCVIII, at nine characters, which matters when you are sizing an engraving.

Roman numerals in Excel and Google Sheets

Both spreadsheets include =ROMAN(number), which returns the standard numeral (so =ROMAN(2026) gives MMXXVI), and =ARABIC(text), which turns a numeral back into a number. Excel's ROMAN takes an optional second argument, from 0 to 4, that produces progressively more concise, non-standard forms. =ROMAN(499) gives the standard CDXCIX, but =ROMAN(499,4) gives ID. If a spreadsheet hands you an unusually short numeral, paste it into the converter above: it reads the value and warns you when the form isn't standard.

Unicode Roman numeral characters

Unicode has dedicated Roman numeral characters in the Number Forms block, from U+2160 (Ⅰ) through U+2188, including single-character forms such as Ⅻ for twelve. They exist mainly for compatibility with older character sets. For the common ones, U+2160 to U+217F, standard compatibility normalization (NFKC) maps each back to ordinary letters, so Ⅻ becomes "XII". Many fonts lack them and screen readers and search engines may not read them as numbers, so for documents, websites and tattoos, type the ordinary capital letters I, V, X, L, C, D and M, which is what this converter outputs.