Roman Numeral Converter - Numbers to Roman Numerals

Convert between Arabic numbers and Roman numerals. Supports numbers 1-3999. Learn the Roman numeral system with interactive conversion and rules.

Number to Roman Numeral

Arabic Number (1-3999)

Roman Numeral

Roman Numeral to Number

Roman Numeral

Arabic Number

Quick Reference

I
1

V
5

X
10

L
50

C
100

D
500

M
1000

Conversion Breakdown

Enter a number to see how it converts step by step

Common Roman Numerals

Number	Roman	Number	Roman
1	I	50	L
2	II	100	C
3	III	500	D
4	IV	1000	M
5	V	1999	MCMXCIX
9	IX	2000	MM
10	X	2024	MMXXIV
40	XL	3000	MMM

Conversion Rules

Basic Rules

Numerals are added when smaller values follow larger: VI = 5+1 = 6
Numerals are subtracted when smaller values precede larger: IV = 5-1 = 4
Only I, X, C, M can be subtracted
I before V or X: IV (4), IX (9)
X before L or C: XL (40), XC (90)
C before D or M: CD (400), CM (900)

Repetition Rules

I, X, C, M can repeat up to 3 times: III = 3, XXX = 30
V, L, D are never repeated

Years in Roman Numerals

Year	Roman
1990	MCMXC
2000	MM
2010	MMX
2020	MMXX
2024	MMXXIV
2025	MMXXV

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Frequently Asked Questions

Standard Roman numerals go up to 3,999 (MMMCMXCIX). Larger numbers used vinculum notation (bar over numeral = multiply by 1000), but this isn't widely supported.

Subtractive notation (IV for 4, IX for 9) was adopted to shorten numerals. However, IIII is sometimes used on clock faces for aesthetic balance.

No, the Roman system has no symbol for zero or negative numbers. These concepts came later with Arabic numerals.

Break them into groups: MCMXCIV = M (1000) + CM (900) + XC (90) + IV (4) = 1994. Larger values come first, subtract when smaller precedes larger.

Clock faces, book chapters, movie sequel numbers (Rocky IV), Super Bowl numbering (LVIII), building cornerstones, outlines (I, II, III), and formal event numbering.

They're terrible for arithmetic. No place value system, no zero, multiplication and division are extremely difficult. Arabic numerals (0-9) are far superior for calculations.

Only I, X, and C can be subtracted. I before V or X, X before L or C, C before D or M. Never subtract more than one digit, and only from the next two higher values.

No. Proper form is CMXCIX (CM + XC + IX). You can only subtract I from V/X, X from L/C, and C from D/M. Subtracting across multiple place values isn't allowed.

Current year (2025) is MMXXV. Movies often use the year of release: 2024 = MMXXIV. Copyright dates on films and TV shows commonly use Roman numerals.

Ancient Romans used V for both the letter and the numeral 5. The letter U evolved later. In numerals, always use V for 5, never U.