Convert between Arabic numbers and Roman numerals — with a step-by-step breakdown showing each symbol and its value.
Running total: 1000 + 900 + 90 + 4 = 1994
Roman numerals use seven symbols: I (1), V (5), X (10), L (50), C (100), D (500), and M (1000). Numbers are built by placing symbols from largest to smallest and adding their values — so III = 3, VIII = 8, and MMXXIV = 2024.
When a smaller symbol appears before a larger one, it is subtracted instead of added. There are six valid subtractive pairs: IV (4), IX (9), XL (40), XC (90), CD (400), and CM (900). This rule keeps numerals shorter — IV instead of IIII for 4.
The subtractive notation IV (5 − 1) was standardised to avoid four consecutive identical symbols. Some ancient inscriptions do use IIII (notably on clock faces), but the modern convention is IV. This converter uses the modern standard.
This converter supports 1–3999 using standard subtractive notation. Numbers from 4000 upward traditionally use vinculum notation (a bar over a symbol to multiply by 1000), which is not part of classical Roman numerals and is outside the scope of this tool.
No — this converter accepts both uppercase (MCMXCIV) and lowercase (mcmxciv) input and treats them identically. The output is always uppercase, which is the modern standard.
This converter translates instantly between everyday Arabic numerals and classical Roman numerals. Type a number to see its Roman equivalent with a symbol-by-symbol breakdown, or paste a Roman numeral to decode it back to digits. Useful for reading dates on monuments, understanding film sequel numbering, or satisfying plain curiosity about an ancient system still in active use.
The main result shows the converted value in large type. Below it, the breakdown table lists each symbol and the amount it contributes, so you can follow exactly how the total is assembled. For number-to-Roman conversions the symbols appear in descending order of value; for Roman-to-number conversions the decoded integer is shown alongside the validated input.
Enter the number 2024.
2024 converts to MMXXIV. The breakdown is M (1000) + M (1000) + X (10) + X (10) + IV (4) = 2024.
The seven symbols are I = 1, V = 5, X = 10, L = 50, C = 100, D = 500, and M = 1000. All other values are built by combining these seven in additive or subtractive patterns.
When a smaller symbol appears immediately before a larger one, it is subtracted rather than added. The six standard subtractive pairs are IV (4), IX (9), XL (40), XC (90), CD (400), and CM (900). This rule is what lets Roman numerals stay compact — writing IX for 9 instead of VIIII.
The classical system runs from 1 to 3999. Numbers of 4000 and above require a vinculum (an overline that multiplies a symbol by 1000), which is rarely printed and has no standard digital representation, so this converter follows the universally accepted 3999 limit.
Yes. You will find them on clock faces, in the credits of films and television productions (production year), on the facades of public buildings, in the numbering of monarchs and popes, for Super Bowl and Olympic editions, and in legal and academic citation styles.
No. The converter accepts both uppercase (XIV) and lowercase (xiv) input and treats them identically. The output is always uppercase, which is the standard written form.
To convert an integer to Roman numerals the calculator works through a fixed table of 13 entries — M (1000), CM (900), D (500), CD (400), C (100), XC (90), L (50), XL (40), X (10), IX (9), V (5), IV (4), I (1) — from largest to smallest. At each step it subtracts the current entry value from the remaining total as many times as possible, appending the matching symbol each time. The greedy descent guarantees the shortest valid representation. To convert in the opposite direction the calculator validates the input against a strict regular expression that enforces the classical rules (M at most three times, D/L/V at most once, correct subtractive pairs only), then scans the string left to right: when a symbol is smaller than the one that follows, it is subtracted; otherwise it is added. The valid range is 1 to 3999.
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