Roman numerals
Convert a number to Roman numerals, or the other way around.
Instantly turn a number into Roman numerals, or read classic or modern Roman notation back into its numeric value.
Settings
Conversion direction
Notation type
Source
Result
Quick explanation
Choose the conversion direction, then the notation type. Classic mode covers 1 to 3999; modern mode accepts overlines for extended thousands.
Try this too
Need another code system?
Try A1Z26 to convert letters into numbers and compare two simple mapping systems.
Additional information
How do Roman numerals work?
Roman numerals use seven main symbols: I, V, X, L, C, D, and M. Values are usually added, except when a smaller symbol appears before a larger one: IV is 4 and IX is 9.
Classic mode
Classic mode uses standard notation from 1 to 3999. It is the recommended mode for dates, centuries, chapter numbers, and most puzzles.
Modern mode
Modern mode uses a vinculum, an overline above the numeral, to multiply a symbol by 1000. For example, V̅ is 5000 and X̅ is 10000.
Subtractive forms
Accepted notation uses the common subtractive pairs: IV, IX, XL, XC, CD, and CM.
Reference table
| Symbol | Value | Symbol | Value |
|---|---|---|---|
| I | 1 | V | 5 |
| X | 10 | L | 50 |
| C | 100 | D | 500 |
| M | 1000 |
Useful examples
Roman numerals are often used for dates, centuries, chapter numbers, puzzles, or clues. For example, XIX is 19, XLII is 42, and MMXXVI is 2026.
In modern mode, larger thousands can be written with a vinculum: V̅I̅I̅XXVI represents 7026. This notation is less common than classic notation, but it makes larger numbers possible without inventing new symbols.
To compare this system with letter-to-number conversion, you can also use A1Z26. To identify several code formats quickly, try the code detector.
For more background, see the Roman numerals article on Wikipedia.
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