Roman Numeral Converter
Convert any number to Roman numerals or any Roman numeral back to a regular number — with a complete reference table and step-by-step breakdown.
Common Years
| 2020 | MMXX | 2021 | MMXXI |
| 2022 | MMXXII | 2023 | MMXXIII |
| 2024 | MMXXIV | 2025 | MMXXV |
| 2026 | MMXXVI | 2027 | MMXXVII |
| 2028 | MMXXVIII | 1994 | MCMXCIV |
Key Numbers & Rules
V 5
X 10
L 50
D 500
M 1000
Subtractive Notation:
I before V or X = 4 (IV) or 9 (IX)
X before L or C = 40 (XL) or 90 (XC)
C before D or M = 400 (CD) or 900 (CM)
Examples
- 2026 → MMXXVI
- 1994 → MCMXCIV
- XIV → 14
- CD → 400
Frequently Asked Questions
What are Roman numerals and why are they still used?
Roman numerals are a number system originating in ancient Rome that uses combinations of letters I V X L C D and M to represent values. They are still used today for clock faces movie and book sequels (Rocky II, Star Wars IV), chapter numbers, copyright years on films and broadcasts, Super Bowl numbering, and formal documents. Understanding Roman numerals is also required for reading historical texts and monuments.
What is subtractive notation in Roman numerals?
Subtractive notation is the rule that allows a smaller value symbol placed before a larger one to mean subtraction. For example IV means 5 minus 1 equals 4 not 6. Only specific combinations are valid: I before V or X, X before L or C, and C before D or M. This rule prevents awkward repetition like IIII for 4 which is replaced by the more elegant IV.
What is the largest number in Roman numerals?
The standard Roman numeral system goes up to 3999 (MMMCMXCIX) using the symbols I V X L C D and M. Numbers above 3999 traditionally used a bar over a symbol to multiply by 1000 but this is rarely used today. This calculator handles numbers from 1 to 3999 which covers all practical uses including years dates and traditional numbering systems.
Why do clocks use IIII instead of IV?
Many clock faces use IIII for four rather than the subtractive IV. This is called clockmaker's notation and has been used since the 14th century. Theories for this preference include visual balance with the VIII on the opposite side, easier manufacturing by using the same mold four times, and avoiding confusion with the Roman numeral for the king (IV in Latin = IVPITER or Jupiter). Both IIII and IV are considered acceptable for clocks.
How do I read Roman numerals in a movie or TV show copyright?
Roman numeral copyright years follow standard notation. The year is broken into thousands hundreds tens and ones. For example MMXXVI means MM (2000) plus XX (20) plus VI (6) equals 2026. A common pattern is that movies from the 1990s often include CM (900) in their copyright making them look more complex — MCMXCIX is 1999.