How to Read and Write Roman Numerals (Including Years Like 2026)

The short answer

Roman numerals use seven letters: I = 1, V = 5, X = 10, L = 50, C = 100, D = 500, M = 1000. You add the values from left to right, except when a smaller letter comes before a larger one, which means subtract (IV = 4, IX = 9, XL = 40, XC = 90, CD = 400, CM = 900). So 2026 is MMXXVI (1000 + 1000 + 10 + 10 + 5 + 1). The Roman Numeral Converter converts in both directions for numbers from 1 to 3999.

The seven symbols

Symbol	Value
I	1
V	5
X	10
L	50
C	100
D	500
M	1000

There is no symbol for zero, and standard Roman numerals stop at 3999 (MMMCMXCIX), because writing 4000 would need four Ms in a row.

The two rules that cover almost everything

Rule 1: add when letters go from big to small

Read left to right. If each letter is the same size or smaller than the one before it, just add them up.

• VIII = 5 + 1 + 1 + 1 = 8
• LXX = 50 + 10 + 10 = 70
• MDCL = 1000 + 500 + 100 + 50 = 1650

Rule 2: subtract when a small letter comes before a bigger one

Only six pairs are used for subtraction in standard numerals:

Pair	Value
IV	4
IX	9
XL	40
XC	90
CD	400
CM	900

That is the full list. I only goes before V and X, X only before L and C, and C only before D and M. V, L and D are never subtracted.

Bonus rule: no more than three in a row

I, X, C and M can repeat up to three times (III = 3, XXX = 30). For 4, 40 and 400 you use the subtraction pairs instead of a fourth repeat. Clock faces that show IIII for 4 are a traditional design choice, not the standard form.

How to write any number, step by step

Break the number into thousands, hundreds, tens and units, convert each part, then join them.

Example: 1947

1000 = M

900 = CM

40 = XL

7 = VII

Join: MCMXLVII

Example: 444

400 = CD

40 = XL

4 = IV

Join: CDXLIV

Here is the full table of building blocks, so you never have to guess:

Place	1	2	3	4	5	6	7	8	9
Units	I	II	III	IV	V	VI	VII	VIII	IX
Tens	X	XX	XXX	XL	L	LX	LXX	LXXX	XC
Hundreds	C	CC	CCC	CD	D	DC	DCC	DCCC	CM
Thousands	M	MM	MMM	–	–	–	–	–	–

How to read a Roman numeral, step by step

Scan from left to right. When a letter is smaller than the next one, subtract it; otherwise add it.

Example: MCMXCIX

M = 1000 (next letter C is smaller, so add)

CM = 900 (C is smaller than M, so subtract C from M)

XC = 90

IX = 9

Total: 1000 + 900 + 90 + 9 = 1999

Years in Roman numerals

Years are the most common reason people need Roman numerals, for film credits, building cornerstones, tattoos, wedding invitations and book copyright pages. These were all produced with the converter:

Year	Roman numeral
1947	MCMXLVII
1950	MCML
1999	MCMXCIX
2000	MM
2024	MMXXIV
2026	MMXXVI

Notice that 1999 is MCMXCIX, not MIM. "Shortcut" forms such as IM for 999 or IC for 99 are not standard.

Using the Roman Numeral Converter

Open the Roman Numeral Converter.

Choose Number → Roman or Roman → Number.

Type the value. The result appears straight away and you can copy it.

Use the example buttons (2024, 1999, 42, 3999) to check how a familiar number looks.

For Number → Roman, the tool accepts whole numbers from 1 to 3999. Zero, negative numbers and anything above 3999 show "Out of range". For Roman → Number, you can type in lower case; letters other than M, D, C, L, X, V and I give "Invalid Roman numeral".

Important: always check the reverse direction

When converting from Roman numerals, the converter adds and subtracts letter values but does not check whether the numeral follows the standard rules. So it will happily give a number for non-standard input:

You type	Converter shows	Standard form
IIII	4	IV
IC	99	XCIX
VX	5	V
XM	990	CMXC
MMMM	4000	not standard (above 3999)

Tip: to make sure a numeral is written correctly, take the number you got, switch to Number → Roman, and convert it back. If the result does not match what you typed, your original was not in standard form. This matters for anything permanent, such as an engraving or a tattoo.

Writing a full date in Roman numerals

For invitations and tattoos, people often want the whole date. Convert the day, month and year separately and keep the separators you normally use. For example, 13.10.2026 becomes XIII.X.MMXXVI (13 = XIII, 10 = X, 2026 = MMXXVI). Decide on the order first: India and the UK write day before month, while the US writes month before day, so the same numerals can be read as two different dates.

Lower-case numerals

Lower-case Roman numerals (i, ii, iii, iv) follow exactly the same rules. You often see them on the preface pages of books and in numbered sub-points of legal documents. The converter accepts lower-case input when converting to a number and always shows its Roman output in capitals.

Common mistakes

• Writing 49 as IL. I can only go before V and X. The correct form is XLIX (40 + 9).
• Writing 99 as IC. It is XCIX (90 + 9).
• Writing 1990 as MXM. It is MCMXC (1000 + 900 + 90).
• Using four of the same letter, such as XXXX for 40. Use XL.
• Copying a year from a source that uses a font where I and l look the same. Retype it in capitals.

Related tools

• Turn a number into English words for cheques and forms with Number to Words.
• Work out someone's age for a birthday or anniversary engraving with the Age Calculator.