Roman Numeral Converter

What Are Roman Numerals?

Roman numerals are a numeral system that originated in ancient Rome and remained the dominant way of writing numbers throughout Europe for nearly two thousand years. Unlike the modern Hindu-Arabic numeral system (0, 1, 2, 3…) which uses ten digits and positional notation, Roman numerals use seven Latin letters — I, V, X, L, C, D, M — combined in additive and subtractive patterns to represent values.

The system evolved from Etruscan numerals used in pre-Roman Italy around the 8th century BCE. The Romans refined it into the notation we recognize today: tally-like marks for small numbers (I, II, III) and shorthand letters for larger values. Despite being replaced by Hindu-Arabic numerals for everyday arithmetic in the Middle Ages, Roman numerals survive in modern life — from Super Bowl numbers and movie copyright dates to clock faces, book chapters, and building cornerstones.

Our converter above handles bidirectional conversion (numbers to Roman and Roman to numbers), date conversion for tattoos and engravings, arithmetic operations in Roman numerals, and a complete reference chart — all in one tool. This replaces the need for multiple separate calculators.

The 7 Roman Numeral Symbols

The entire Roman numeral system is built from just seven symbols. Every Roman numeral — from I (1) to MMMCMXCIX (3,999) — is constructed by combining these letters:

Symbol	Value	Name (Latin)	Origin
I	1	Unus	A single tally mark — one finger held up
V	5	Quinque	An open hand (5 fingers) — the top half of an X
X	10	Decem	Two V's stacked or crossed — two hands
L	50	Quinquaginta	Originally ⊥ (half of the old symbol for 100), later stylized to L
C	100	Centum	From Latin centum (hundred)
D	500	Quingenti	Half of the old symbol for 1000 (IↃ → D)
M	1,000	Mille	From Latin mille (thousand)

There is no symbol for zero in Roman numerals. The concept of zero as a placeholder did not exist in Roman mathematics — it was introduced to Europe through the Hindu-Arabic system via Arab scholars in the Middle Ages.

How to Convert Numbers to Roman Numerals

Converting a number to Roman numerals follows a place-value decomposition method. Break the number into thousands, hundreds, tens, and ones, convert each place separately, then concatenate the results. Here is the step-by-step algorithm:

1. Break down by place value: Separate the number into thousands, hundreds, tens, and ones. For example, 2,749 = 2,000 + 700 + 40 + 9.
2. Convert each place value: Use the conversion chart below for each digit position.
3. Concatenate left to right: Join the Roman numeral groups from largest (thousands) to smallest (ones).

Place Value Conversion Chart

Ones	Tens	Hundreds	Thousands
1 = I	10 = X	100 = C	1000 = M
2 = II	20 = XX	200 = CC	2000 = MM
3 = III	30 = XXX	300 = CCC	3000 = MMM
4 = IV	40 = XL	400 = CD
5 = V	50 = L	500 = D
6 = VI	60 = LX	600 = DC
7 = VII	70 = LXX	700 = DCC
8 = VIII	80 = LXXX	800 = DCCC
9 = IX	90 = XC	900 = CM

Worked Example: Convert 2,026 to Roman Numerals

1. Thousands: 2,000 = MM
2. Hundreds: 0 = (nothing)
3. Tens: 20 = XX
4. Ones: 6 = VI

Combine: MM + XX + VI = MMXXVI

Worked Example: Convert 1,999 to Roman Numerals

1. Thousands: 1,000 = M
2. Hundreds: 900 = CM (subtractive: 1000 − 100)
3. Tens: 90 = XC (subtractive: 100 − 10)
4. Ones: 9 = IX (subtractive: 10 − 1)

Combine: M + CM + XC + IX = MCMXCIX

Worked Example: Convert 1,776 to Roman Numerals

The year the United States Declaration of Independence was signed:

1. Thousands: 1,000 = M
2. Hundreds: 700 = DCC
3. Tens: 70 = LXX
4. Ones: 6 = VI

Combine: M + DCC + LXX + VI = MDCCLXXVI

How to Convert Roman Numerals to Numbers

To convert a Roman numeral back to a number, read it from left to right and apply two rules:

1. Additive rule: If a symbol has a value greater than or equal to the symbol to its right, add its value.
2. Subtractive rule: If a symbol has a value less than the symbol to its right, subtract its value from the next symbol's value.

Worked Example: Convert MCMXCIV to a Number

Position	Symbol	Value	Rule	Running Total
1	M	1,000	M ≥ C → Add	1,000
2–3	CM	900	C < M → Subtract (1000−100)	1,900
4–5	XC	90	X < C → Subtract (100−10)	1,990
6–7	IV	4	I < V → Subtract (5−1)	1,994

MCMXCIV = 1,994

Additive vs. Subtractive Notation

Roman numerals use two complementary principles: additive notation and subtractive notation.

Additive Notation

In additive notation, the values of the symbols are simply added together. Symbols are written from largest to smallest (left to right). Examples:

• VIII = 5 + 1 + 1 + 1 = 8
• LXII = 50 + 10 + 1 + 1 = 62
• MDCLXVI = 1000 + 500 + 100 + 50 + 10 + 5 + 1 = 1,666

Subtractive Notation

Subtractive notation prevents the need to write four identical symbols in a row. When a smaller symbol appears before a larger one, you subtract the smaller from the larger. There are only six valid subtractive combinations:

Combination	Value	Replaces
IV	4	IIII
IX	9	VIIII
XL	40	XXXX
XC	90	LXXXX
CD	400	CCCC
CM	900	DCCCC

Why 99 Is XCIX, Not IC

A common question is: why can't you write 99 as "IC" (100 − 1)? The answer lies in a strict rule:

Therefore, 99 must be written as XC (90) + IX (9) = XCIX. Similarly, 490 is CDXC (not XD) and 999 is CMXCIX (not IM). Each digit place must be expressed independently.

The Four-in-a-Row Prohibition

In standard (subtractive) notation, no symbol may appear more than three times in a row. For example:

• III = 3 ✅ (three I's)
• IV = 4 ✅ (not IIII)
• XXX = 30 ✅ (three X's)
• XL = 40 ✅ (not XXXX)

Exception: On many clock and watch faces, the number 4 is written as IIII rather than IV. This is called the "clockmaker's four" or "watchmaker's convention." Theories for this include visual symmetry with VIII on the opposite side of the dial, readability, and tradition dating back to medieval times. Our calculator uses the standard subtractive notation (IV for 4).

Roman Numerals in American Culture

Despite being thousands of years old, Roman numerals remain deeply embedded in American life. Here are the most common places you'll encounter them in the United States:

Super Bowl Numbering

The National Football League (NFL) has used Roman numerals to number the Super Bowl since Super Bowl V (1971). This tradition adds gravitas and makes each game feel historic. Super Bowl LVIII (58) was played in February 2024 at Allegiant Stadium in Las Vegas. The only exception was Super Bowl 50 (2016), which used an Arabic numeral 50 for aesthetic reasons before returning to Roman numerals with Super Bowl LI (51). Use our converter to find any Super Bowl number — for example, Super Bowl C will be the 100th.

Movie and Television Copyright Dates

Hollywood has traditionally used Roman numerals in the copyright notice at the end of films and TV shows. The year the film was produced appears in Roman numerals — for example, MCMXCIX for 1999 or MMXXVI for 2026. This practice dates back to the early studio system and continues today, though some studios have switched to Arabic numerals.

Clock and Watch Faces

Roman numeral clock faces have been standard since medieval Europe and remain popular in the United States on wall clocks, wristwatches, and tower clocks (like many city hall and courthouse clocks across America). Most use IIII for 4 instead of IV — a centuries-old tradition called the "watchmaker's four."

Government Buildings and Monuments

Many U.S. government buildings, courthouses, and memorials display the year of construction or dedication in Roman numerals carved into the cornerstone or pediment. The Supreme Court Building, the Library of Congress, and countless state capitols feature Roman numeral dates. University buildings and public libraries throughout the country also follow this tradition.

Tattoo and Jewelry Trends

Roman numeral tattoos are consistently among the most popular tattoo styles in the United States. Common designs include birthdates, wedding dates, memorial dates, and coordinates. Our Date Converter tab is designed specifically for this use case — enter any date and get the Roman numeral equivalent with your choice of separator for the perfect tattoo, engraving, or invitation design.

Education, Outlines, and Chapters

Roman numerals are used extensively in academic outlines (I, II, III for major sections), book chapters, act and scene numbers in plays, and music theory (chord numbers in harmonic analysis). The mathematical education system in the United States teaches Roman numerals as part of the K-6 curriculum.

Numbers Greater Than 3,999 — The Overline (Vinculum)

The largest number that can be written using the standard seven symbols without repetition rules being broken is 3,999 = MMMCMXCIX. To represent larger numbers, Romans used an overline (called a vinculum) placed above a symbol. An overline multiplies the symbol's value by 1,000.

Overline Symbol	Value	Standard Symbol	× 1,000
I̅	1,000	I = 1	1 × 1,000
V̅	5,000	V = 5	5 × 1,000
X̅	10,000	X = 10	10 × 1,000
L̅	50,000	L = 50	50 × 1,000
C̅	100,000	C = 100	100 × 1,000
D̅	500,000	D = 500	500 × 1,000
M̅	1,000,000	M = 1,000	1,000 × 1,000

This extends the range to 3,999,999. Our converter supports overline notation — enter any number up to 3,999,999 to see its Roman numeral with combining overline characters.

Common Mistakes and Misconceptions

Here are the most common errors people make when working with Roman numerals:

1. Writing IIII for 4: In standard notation, 4 is IV, not IIII. Exception: clock faces often use IIII by tradition.
2. Writing IC for 99: I can only subtract from V and X. The correct form is XCIX (90 + 9).
3. Writing VX for 5: V is never subtracted. There is no "VX" — only V (5) exists.
4. Expecting a zero: Roman numerals have no zero. The concept did not exist in Roman mathematics.
5. Exceeding three in a row: XXXX is not standard; use XL for 40. CCCC is not standard; use CD for 400.
6. Mixing cases: Roman numerals should be all uppercase. Lowercase may be used for page numbering (i, ii, iii) in books.
7. Confusing D and M: D = 500, M = 1,000. A common mix-up that produces wildly wrong values.

Roman Numerals Chart: 1 to 100

Here is the complete reference table for Roman numerals 1 to 100. You can also use our Reference Chart tab above to search for any number or view ranges like 1–50, 51–100, 100–500, and 500–1,000.

Number	Roman	Number	Roman	Number	Roman	Number	Roman
1	I	26	XXVI	51	LI	76	LXXVI
2	II	27	XXVII	52	LII	77	LXXVII
3	III	28	XXVIII	53	LIII	78	LXXVIII
4	IV	29	XXIX	54	LIV	79	LXXIX
5	V	30	XXX	55	LV	80	LXXX
6	VI	31	XXXI	56	LVI	81	LXXXI
7	VII	32	XXXII	57	LVII	82	LXXXII
8	VIII	33	XXXIII	58	LVIII	83	LXXXIII
9	IX	34	XXXIV	59	LIX	84	LXXXIV
10	X	35	XXXV	60	LX	85	LXXXV
11	XI	36	XXXVI	61	LXI	86	LXXXVI
12	XII	37	XXXVII	62	LXII	87	LXXXVII
13	XIII	38	XXXVIII	63	LXIII	88	LXXXVIII
14	XIV	39	XXXIX	64	LXIV	89	LXXXIX
15	XV	40	XL	65	LXV	90	XC
16	XVI	41	XLI	66	LXVI	91	XCI
17	XVII	42	XLII	67	LXVII	92	XCII
18	XVIII	43	XLIII	68	LXVIII	93	XCIII
19	XIX	44	XLIV	69	LXIX	94	XCIV
20	XX	45	XLV	70	LXX	95	XCV
21	XXI	46	XLVI	71	LXXI	96	XCVI
22	XXII	47	XLVII	72	LXXII	97	XCVII
23	XXIII	48	XLVIII	73	LXXIII	98	XCVIII
24	XXIV	49	XLIX	74	LXXIV	99	XCIX
25	XXV	50	L	75	LXXV	100	C

Important Years in Roman Numerals

Here are historically significant years for the United States and commonly searched year conversions:

Year	Roman Numeral	Event
1776	MDCCLXXVI	Declaration of Independence
1865	MDCCCLXV	End of the Civil War
1969	MCMLXIX	Moon landing (Apollo 11)
1999	MCMXCIX	End of the 20th century
2000	MM	New millennium
2024	MMXXIV	Current era
2025	MMXXV	Current era
2026	MMXXVI	Current era