Roman Numeral Converter
Convert numbers, dates, and multiple values to Roman numerals and back
Number Converter
Result will appear here
Roman Numeral Basics
- Roman numerals use combinations of I, V, X, L, C, D, M
- Numbers above 3999 require special notation
- Subtractive notation is used (e.g., IV for 4, IX for 9)
Date Converter
Date result will appear here
Date Conversion Notes
- Use – . \ / | or space as separators
- Years are converted as whole numbers
- Month can be numeric (1-12) or name (Jan, January)
- BCE dates are supported with negative years
Roman Numeral Reference
| Number | Roman Numeral | Number | Roman Numeral | Number | Roman Numeral |
|---|---|---|---|---|---|
| 1 | I | 20 | XX | 400 | CD |
| 2 | II | 40 | XL | 500 | D |
| 3 | III | 50 | L | 900 | CM |
| 4 | IV | 90 | XC | 1000 | M |
| 5 | V | 100 | C | 2023 | MMXXIII |
| 9 | IX | 200 | CC | 3999 | MMMCMXCIX |
| 10 | X | 300 | CCC |
How to Read Roman Numerals
- I = 1, V = 5, X = 10, L = 50
- C = 100, D = 500, M = 1000
- When a smaller numeral is before a larger one, subtract (IV = 4, IX = 9)
- Numerals are usually written from largest to smallest (MMXXIII = 2023)
- A bar over a numeral multiplies it by 1000 (not supported in standard notation)