Roman Numerals Converter — Arabic to Roman & Back

Guide

About Roman Numerals

Convert between Arabic and Roman numerals — 1 to 3,999,999. Numbers above 3,999 use vinculum (overline) notation to multiply by 1,000. Useful for copyright years, movie sequels, sports championships, and any time you need to encode a number with the weight of antiquity.

The seven symbols

Symbol	Value
I	1
V	5
X	10
L	50
C	100
D	500
M	1,000

Subtractive pairs

IV (4), IX (9)
XL (40), XC (90)
CD (400), CM (900)

Roman numerals chart (1–10)

Arabic	Roman	Arabic	Roman
1	I	6	VI
2	II	7	VII
3	III	8	VIII
4	IV	9	IX
5	V	10	X

Roman numerals 1–20 and the tens

#	Roman	#	Roman	Tens	Roman
11	XI	16	XVI	10	X
12	XII	17	XVII	20	XX
13	XIII	18	XVIII	30	XXX
14	XIV	19	XIX	40	XL
15	XV	20	XX	50	L

Hundreds follow the same pattern: 60 = LX, 90 = XC, 100 = C, 400 = CD, 500 = D, 900 = CM, 1000 = M.

What the letters mean

I = 1, V = 5, X = 10, L = 50, C = 100, D = 500, M = 1000.
IV = 4, VI = 6, IX = 9, LX = 60. So what is IV? Four. What is LX? Sixty. What is C? One hundred.

Roman numerals that multiply to 35

A common puzzle: which Roman numerals multiply to 35? Since 35 = 5 × 7, the answer is V × VII. (The trivial pair 1 × 35 is I × XXXV.) Type 35 above to see it render, or 5 and 7 to confirm the factors.

How to read Roman numerals

Scan left to right and add — but when a smaller symbol precedes a larger one, subtract it instead:

MCMLXXXIV → M + CM + LXXX + IV → 1000 + 900 + 80 + 4 → 1984

Three rules cover almost everything: a symbol repeats at most three times, only I/X/C are used subtractively, and you never subtract across more than one order of magnitude (so 99 is XCIX, not IC).

Roman numeral tattoos

Date tattoos (birthdays, anniversaries) are the most common use. Format the day, month, and year separately — e.g. 14 March 2019 becomes XIV · III · MMXIX. Convert each part above, and double-check the subtractive forms (IV, IX, XL) before committing to ink — the classic mistake is writing IIII for 4.

Common workflows

Movie sequel year. Rocky IV (4) — IV. Star Wars Episode IX (9) — IX.

Copyright year. © MMXXV — 2025.

Super Bowl. Super Bowl LVIII — 58. Super Bowl LX — 60.

Outline numbering. Top-level Roman, sub-level letter, sub-sub Arabic. The tool pins the conversion.

Why Romans don’t add up

The numeral system is positional only loosely (subtractive notation breaks pure positional). Adding two Roman numerals is harder than adding two Arabic-Indian numerals — and that is exactly why the world switched to Arabic-Indian. Roman numerals survive as decoration; Arabic-Indian rules math.

Frequently asked questions

Which year is MMXXV?

2025. M = 1000, X = 10, V = 5 — so M+M+X+X+V = 2025.

Why do some numbers use subtraction?

To avoid four-in-a-row. 4 is IV (5 minus 1), not IIII. 9 is IX. 40 is XL. 90 is XC. 400 is CD. 900 is CM.

How to write 4,000?

Above 3,999, classical Roman numerals run out. We use vinculum (overline) — I̅V̅ means 4 × 1,000 = 4,000. Or you can switch to mixed Arabic/Roman.

Romans never had a zero?

Correct. Their math was concrete, not symbolic. Zero entered European math through Arabic-Indian numerals around the 12th century.

Can clocks have IIII for 4?

Yes — clock faces traditionally use IIII for 4 (visual balance with VIII for 8). Both forms are accepted; the tool defaults to IV but offers a toggle.

Performance for big numbers?

Up to 3,999,999 cleanly. Above that, the vinculum gets unwieldy.

What Roman numerals multiply to 35?

V × VII. 35 factors as 5 × 7, and in Roman numerals 5 is V and 7 is VII — so V × VII = 35 (the other factor pair, 1 × 35, is I × XXXV).

How do you read Roman numerals?

Read left to right, adding values — except when a smaller symbol sits before a larger one, then subtract it. So MCMLXXXIV = M(1000) + CM(900) + LXXX(80) + IV(4) = 1984. Rule of thumb: a symbol can repeat up to three times, and only I, X, C are used subtractively (before the next one or two larger symbols).

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Last updated: 2026-07-04