Roman Numeral Converter

Convert integers to Roman numerals and back — range 1 to 3999

Enter any integer from 1 to 3999 to get its Roman numeral, or type a Roman numeral to convert it back to a number. The complete step-by-step decomposition is shown.

Try: 1 · 4 · 9 · 14 · 42 · 1999 · 2024 · 3999

Roman numeral symbols

Symbol IVXLCDM
Value 1510501005001000
Subtractive combinations IVIXXLXCCDCM
Value 494090400900

About Roman numerals

How Roman numerals work

Roman numerals use seven letters: I = 1, V = 5, X = 10, L = 50, C = 100, D = 500, M = 1000. Numbers are formed by writing symbols from largest to smallest — with a subtractive rule: a smaller symbol placed before a larger one means subtraction.

The six subtractive combinations are: IV = 4, IX = 9, XL = 40, XC = 90, CD = 400, CM = 900.

Limits of the system

Standard Roman numerals cover integers from 1 to 3999. Numbers beyond 3999 would require MMMM (four Ms) which breaks the rule of repeating a symbol no more than three times consecutively. Zero and negative numbers have no Roman numeral representation.

A brief history

Roman numerals evolved from the Etruscan numeral system around the 7th century BCE. They were the standard system throughout the Roman Empire and remained widely used in Europe until the 13th–15th centuries, when the Hindu-Arabic numeral system took over. Today they appear on clock faces, building cornerstones, book prefaces (page i, ii, iii…), Super Bowl numbering, and movie copyright years.

Frequently asked questions

2024 in Roman numerals is MMXXIV. Decomposition: MM (2000) + XX (20) + IV (4).
Using standard notation, the largest number is 3999 = MMMCMXCIX. The value 4000 would require MMMM — four Ms in a row — which breaks the rule of repeating a symbol no more than three times.
The subtractive rule: IV places a smaller symbol (I = 1) before a larger one (V = 5), meaning 5 − 1 = 4. This avoids four consecutive identical symbols and applies to 4, 9, 40, 90, 400, and 900. Note: clock faces often still use IIII for aesthetic balance.
No. The Roman numeral system has no symbol for zero. Medieval scholars sometimes used the Latin word nulla ("nothing"), but there was no standard positional notation.
Read the symbols from right to left: if a symbol is smaller than the one to its right, subtract it; otherwise add it. Example: XIV → from right to left: V(5), I(1) < V(5) so subtract, X(10). Result: 10 + 5 − 1 = 14.
Yes. Roman numerals appear on clock faces (XII, VI…), Super Bowl and Olympic numbering, movie copyright years, monarchs and popes (e.g. Charles III, John XXIII), and introductory pages of books (i, ii, iii, iv…).

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