Roman Numeral Converter
Arabic ⇄ Roman · Both directions
Arabic Number
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Roman Numerals
Step-by-Step Breakdown
Reference Table: click any to convert
How to Read and Write Roman Numerals
Roman numerals use seven letters (I = 1, V = 5, X = 10, L = 50, C = 100, D = 500, M = 1,000), and you convert one place value at a time: 2026 = MM + XX + VI = MMXXVI. Type a whole number from 1 to 3,999 or a numeral above and the converter shows the other form with a step-by-step breakdown.
Convert one place value at a time, from thousands down to ones, and join the pieces. Each digit of the ordinary number maps to a fixed group of letters, shown in the table below. Reading works the other way round: split the numeral into those groups and add them up.
Roman Numerals by Place Value
Find each digit of your number in its column and write the letters from left to right. A blank means that place is zero and you write nothing.
| Digit | Thousands | Hundreds | Tens | Ones |
|---|---|---|---|---|
| 1 | M | C | X | I |
| 2 | MM | CC | XX | II |
| 3 | MMM | CCC | XXX | III |
| 4 | n/a | CD | XL | IV |
| 5 | n/a | D | L | V |
| 6 | n/a | DC | LX | VI |
| 7 | n/a | DCC | LXX | VII |
| 8 | n/a | DCCC | LXXX | VIII |
| 9 | n/a | CM | XC | IX |
Worked Examples
1987 to Roman numerals
1 thousand = M, 9 hundreds = CM, 8 tens = LXXX, 7 ones = VII. Joined up: MCMLXXXVII.
444 to Roman numerals
4 hundreds = CD, 4 tens = XL, 4 ones = IV, so 444 = CDXLIV. Each 4 needs its own subtractive pair.
Reading MCMXCIV
Split it into groups: M (1,000) + CM (900) + XC (90) + IV (4) = 1994. Whenever a smaller letter sits before a larger one, treat the two as a single group.
Years and numbers people look up
| Number | Roman | Number | Roman |
|---|---|---|---|
| 1776 | MDCCLXXVI | 2020 | MMXX |
| 1900 | MCM | 2025 | MMXXV |
| 1950 | MCML | 2026 | MMXXVI |
| 1999 | MCMXCIX | 2027 | MMXXVII |
| 2000 | MM | 2030 | MMXXX |
| 2010 | MMX | 3999 | MMMCMXCIX |
| 49 | XLIX | 60 | LX |
| 99 | XCIX | 500 | D |
Invalid Numerals and Edge Cases
Each number from 1 to 3,999 has exactly one standard numeral, and the converter only accepts that form. When you type something else, it tells you the value it reads and the correct way to write it.
- IIII reads as 4 but is written IV. Clock faces often use IIII by tradition, which is a design choice, not the standard.
- VX would mean 10 minus 5, but V is never used to subtract. Five is simply V.
- IC for 99 skips too far. I can only come before V or X, so 99 is XC + IX = XCIX. In the same way 49 is XLIX, not IL.
- VV, LL, DD are never used, since X, C and M already exist. More than three of the same letter in a row, as in XXXX, is also wrong: 40 is XL.
- MMMM (4,000) and above fall outside the standard system. Romans wrote large numbers with a bar over a letter to multiply it by 1,000, which plain text cannot show.
- Zero, fractions and negative numbers have no Roman numeral, so the converter asks for a whole number from 1 to 3,999.
Roman numerals are a notation, not a way to calculate. For arithmetic on the values, convert first and then use the percentage calculator or fraction calculator as needed.
Method and sources. Conversion uses the standard modern convention: the seven symbols I, V, X, L, C, D and M, at most three repeats of I, X, C and M, and only the six subtractive pairs IV, IX, XL, XC, CD and CM. Numerals are built greedily from 1,000 down to 1, and every numeral typed in is converted back to check it is in standard form. All values above were generated with the same algorithm the converter uses.
Roman Numerals Explained
The seven symbols: I = 1, V = 5, X = 10, L = 50, C = 100, D = 500, M = 1,000. All other numbers are formed by combining these seven symbols. A useful mnemonic to remember the order is "I Value Xylophones Like Cows Drink Milk" (I, V, X, L, C, D, M). The system originated in ancient Rome and remained in widespread use throughout the Middle Ages.
When a smaller symbol appears immediately before a larger one, it is subtracted rather than added. The six valid subtractive combinations are: IV = 4, IX = 9, XL = 40, XC = 90, CD = 400, CM = 900. Only these specific pairs are standard: you cannot write IC for 99 (must be XCIX) or VX (invalid). The subtractive notation developed to avoid writing four identical symbols in a row (IIII, XXXX, etc.).
Roman numerals appear on clock faces (I through XII), book chapter and section numbering, movie sequel titles (Rocky II, Star Wars Episode IV), Super Bowl numbers (Super Bowl LX in 2026), Olympiad numbers (Paris 2024 hosted the Games of the XXXIII Olympiad), monarchs and popes (King Charles III, Pope John Paul II), building construction dates on cornerstones, and copyright years in film credits. They also appear in formal outlines and are used as decorative numerals on monuments and public buildings.
This is one of the most common exceptions to standard Roman numeral rules. Clockmakers traditionally used IIII instead of IV for several reasons: aesthetic symmetry (IIII balances VIII visually on the opposite side of the clock face), historical inertia (early clocks used IIII), and practical reasons (some claim it was easier to read the angle of the clock hands with IIII). King Louis XIV of France is also said to have preferred IIII. Both IIII and IV are used on different clock designs today.
Using the standard seven symbols and their subtractive combinations, the largest number is MMMCMXCIX = 3,999. Romans handled larger numbers using a bar (vinculum) over a letter to multiply by 1,000: V with a bar = 5,000, M with a bar = 1,000,000. Some extended systems use parentheses to indicate multiplication by 1,000. There is no Roman numeral for zero; zero reached Europe with the Hindu-Arabic numerals.
2026 in Roman numerals is MMXXVI. Breaking it down: MM = 2,000 (two thousands). XX = 20 (two tens). VI = 6 (5 + 1). Total: 2,000 + 20 + 6 = 2,026. Other recent years: 2024 = MMXXIV, 2025 = MMXXV, 2027 = MMXXVII, 2030 = MMXXX, 2050 = MML, 2100 = MMC.
4 = IV (5 minus 1). 9 = IX (10 minus 1). This subtractive principle extends to higher denominations: 40 = XL (50 minus 10), 90 = XC (100 minus 10), 400 = CD (500 minus 100), 900 = CM (1,000 minus 100). Memorizing these six subtractive pairs is the key to reading and writing any Roman numeral from 1 to 3,999.
Key rules: (1) A symbol can be repeated up to 3 times in a row (III = 3, XXX = 30, CCC = 300, MMM = 3,000). (2) V, L, and D are never repeated. (3) The subtractive notation uses only I before V and X, only X before L and C, and only C before D and M. (4) Symbols are generally written from largest to smallest, left to right. (5) When a smaller symbol precedes a larger one, the smaller is subtracted. These rules ensure each number has a unique Roman numeral representation.
Roman numerals developed from Etruscan numerals around 500 BC. The symbols evolved from tally marks: I is a single tally, V represents a hand (five fingers), X is two V's (two hands = ten). The system was used throughout the Roman Empire and continued in use across Europe for about a thousand years after Rome's fall. The Hindu-Arabic numeral system (0-9) gradually replaced Roman numerals in Europe from the 13th century onward, though Roman numerals persist in specialized contexts to this day.
Work from largest to smallest denomination. 1,999: Start with M = 1,000. Remaining: 999. Next: CM = 900. Remaining: 99. Next: XC = 90. Remaining: 9. Next: IX = 9. Result: MCMXCIX. Verification: M(1000) + CM(900) + XC(90) + IX(9) = 1,999. The general approach is to find the largest Roman numeral value that fits, write its symbol, subtract, and repeat with the remainder.
I, II, III, IV, V, VI, VII, VIII, IX, X for 1 to 10, then XI, XII, XIII, XIV, XV, XVI, XVII, XVIII, XIX, XX for 11 to 20. The pattern repeats: 4 and 9 use subtraction (IV, IX), and 11 to 19 are X followed by the numeral for 1 to 9.
Split it into place value groups, treating any smaller letter before a larger one as a pair. MCMXCIV = M (1,000) + CM (900) + XC (90) + IV (4) = 1994. Film credits and building cornerstones usually start with M or MM, so the first letters give you the century: MCM is 1900s, MM is 2000s.