Convert any number from 1 to 3999 into Roman numerals, or convert Roman numerals back to numbers, with a clear step-by-step breakdown.
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The converter uses a greedy algorithm with the thirteen standard Roman values (1000, 900, 500, 400, 100, 90, 50, 40, 10, 9, 5, 4, 1). For a number, it repeatedly subtracts the largest value that fits and appends the matching symbol, which naturally produces the subtractive pairs IV, IX, XL, XC, CD and CM. In the reverse direction it scans the Roman numeral right to left, adding each symbol's value and subtracting it when a smaller symbol precedes a larger one, so MCMXCIV correctly evaluates to 1994. Input is limited to the standard 1 to 3999 range.
Pick a conversion mode first. This free Roman numeral calculator also works as a translator between the two numbering systems. In Number to Roman mode, type any whole number from 1 to 3999, for example 2024, and the tool returns MMXXIV with a place-value breakdown of 2000 + 20 + 4 so you can see exactly how the result was built. In Roman to Number mode, type a numeral such as MCMXCIV and the tool returns 1994. The converter accepts lowercase letters and ignores extra spaces. Standard Roman numerals end at 3999 (MMMCMXCIX); for larger values, the historical system used an overline (vinculum) to multiply a symbol by 1000.
Every Roman numeral is built from just seven letters of the Latin alphabet: I = 1, V = 5, X = 10, L = 50, C = 100, D = 500 and M = 1000. In general, symbols are written from largest to smallest and their values are added, so VI = 6, XII = 12 and CLXXV = 175. This seven-symbol chart is the foundation for reading and writing every numeral from 1 to 3999. Bookmark it as a quick reference whenever you check a conversion.
When a smaller symbol sits before a larger one, it is subtracted instead of added. Only six such pairs are valid: IV = 4, IX = 9, XL = 40, XC = 90, CD = 400 and CM = 900. The subtractive notation rules are strict: only I, X and C can be subtracted; I may only precede V and X, X may only precede L and C, and C may only precede D and M. This is why 4 is IV rather than IIII, 9 is IX, 40 is XL and 900 is CM.
Reading becomes easy once you split a numeral into its parts. 2024 = MM + XX + IV = MMXXIV. 1994 = M + CM + XC + IV = MCMXCIV, the classic triple-subtraction example. 1999 = M + CM + XC + IX = MCMXCIX. 1987 = MCMLX X XVII and 365 = CCCLXV follow the same additive pattern. Recent years convert cleanly too: 2024 = MMXXIV, 2025 = MMXXV and 2026 = MMXXVI. The longest standard numeral is 3888 = MMMDCCCLX X XVIII at 15 characters. Two famous traps: 49 is XLIX, not IL, and 99 is XCIX, not IC, because I can only be subtracted from V and X.
The first ten numerals are I, II, III, IV, V, VI, VII, VIII, IX and X. The teens climb as XI, XII, up to XIX = 19, and the twenties to nineties repeat the pattern with X, XX, X X X for 10, 20, 30 and L, LX, LXX, LX X X for 50 through 80. Key landmarks: XL = 40, L = 50, LV = 55, XC = 90, XCIX = 99 and C = 100. Milestones beyond: D = 500 and M = 1000. Practising these blocks makes numerals like X X XVII = 37 and MCMLX X XIV = 1984 readable at a glance.
Roman numerals survive in many modern places. They number Super Bowl games, appear in movie copyright years in the credits, mark the chapters and volume numbers of books, and name monarchs and popes. Clock faces traditionally use them, often with IIII instead of IV for visual balance. They are popular for tattoos and commemorating a date of birth in Roman numerals, which is why date conversion is one of the most requested uses. They also label outlines, sequels and recurring events.
Roman numerals were developed in ancient Rome, likely evolving from Etruscan tally marks, and dominated European counting and commerce for well over a thousand years. The system has no zero, no place value and no fractions, which made arithmetic clumsy and eventually gave way to Arabic numerals around the 1300s. Even so, the symbols endured in clocks, inscriptions, formal documents and ceremonial numbering, which is why a Roman numeral converter remains a handy everyday tool centuries later.
Roman numerals are a number system from ancient Rome that uses seven letters as symbols: I (1), V (5), X (10), L (50), C (100), D (500) and M (1000). Symbols are normally written from largest to smallest and added together, with a smaller symbol before a larger one meaning subtraction, as in IV = 4. The system has no zero and covers the standard range 1 to 3999.
Split the number into thousands, hundreds, tens and ones, then replace each part with its Roman form and join them. For example, 2024 = 2000 + 20 + 4 = MM + XX + IV = MMXXIV. Use the Number to Roman mode above and the tool shows this step-by-step breakdown for any value from 1 to 3999.
By the subtractive notation rules, a smaller symbol before a larger one is subtracted, so IV means 5 minus 1 = 4. Only I, X and C may be subtracted, and I may only precede V and X. Clock faces are a famous exception where IIII is used for visual symmetry, but in standard writing 4 is always IV and 9 is IX.
Because subtraction has strict limits: I can only be subtracted from V (giving IV = 4) and X (giving IX = 9). To write 99 you subtract from the largest values allowed: 90 is XC and 9 is IX, so 99 = XCIX. IC is never valid, just as IL for 49 is never valid; 49 is written XLIX instead.
The largest standard Roman numeral is 3999 = MMMCMXCIX. The seven-symbol system stops at M = 1000, and numerals are not repeated more than three times, so 3999 is the ceiling for ordinary conversion. Larger values historically used a vinculum, an overline multiplying a symbol by 1000.
No. The Roman system has no symbol for zero, no negative numbers and no fractions. The Romans simply did not need a zero in their numbering, which is one reason Arabic numerals replaced Roman ones for calculation. A converter therefore only accepts positive whole numbers from 1 to 3999.
They number Super Bowls, date movie copyright years, label book chapters and volume numbers, identify monarchs and popes, and mark clock faces. People also use them in tattoos, often converting a date of birth to Roman numerals. Outlines, sequels and formal events keep the tradition alive.
1984 = 1000 + 900 + 80 + 4 = M + CM + LX X X + IV = MCMLX X XIV. Reading tip: split the numeral into its largest-value groups first. Similarly, 1980 = MCMLX X X, LV = 55, XI = 11, XIX = 19 and X X XVII = 37. The Roman to Number mode above reads any numeral from 1 to 3999 for you.