Roman Numeral Converter
Convert between decimal numbers and Roman numerals (1 - 3,999)
Roman Numeral Converter
Enter a number (1-3999) to convert to Roman numerals
Roman Numeral Symbols
| Symbol | Value | Name |
|---|---|---|
| I | 1 | One |
| V | 5 | Five |
| X | 10 | Ten |
| L | 50 | Fifty |
| C | 100 | One Hundred |
| D | 500 | Five Hundred |
| M | 1000 | One Thousand |
Common Years in Roman Numerals
| Year | Roman Numeral |
|---|---|
| 2020 | MMXX |
| 2021 | MMXXI |
| 2022 | MMXXII |
| 2023 | MMXXIII |
| 2024 | MMXXIV |
| 2025 | MMXXV |
| 2026 | MMXXVI |
| 2027 | MMXXVII |
| 2028 | MMXXVIII |
| 2029 | MMXXIX |
| 2030 | MMXXX |
How Roman Numerals Work
1. Addition Rule
When a symbol appears after a larger (or equal) symbol, add its value. Example: VII = 5 + 1 + 1 = 7
2. Subtraction Rule
When a smaller symbol appears before a larger symbol, subtract the smaller value. Example: IV = 5 - 1 = 4, XC = 100 - 10 = 90
3. Repetition Rule
A symbol can be repeated up to 3 times in a row. III = 3, XXX = 30. Never repeat V, L, or D.
4. Valid Subtractive Pairs
Only these subtractive combinations are valid: IV (4), IX (9), XL (40), XC (90), CD (400), CM (900). You cannot write IC for 99 — it must be XCIX.
5. Maximum Value
Standard Roman numerals can only represent numbers from 1 to 3,999 (MMMCMXCIX). There is no symbol for zero, and numbers 4,000+ require extended notation with vinculum (overline bars).
Frequently Asked Questions
Why is there no Roman numeral for zero?
The Roman numeral system was developed by the ancient Romans, who did not have a concept of zero as a number. The concept of zero originated in India and was introduced to Europe through Arabic mathematics centuries later. Since Roman numerals were designed for counting and record-keeping rather than abstract mathematics, zero was never needed.
What is the largest number you can write in Roman numerals?
Using standard Roman numeral notation, the largest number is 3,999 (MMMCMXCIX). For numbers 4,000 and above, the ancient Romans used a vinculum — a bar placed over a numeral to multiply its value by 1,000. For example, V with a bar means 5,000. However, this extended notation is rarely used today.
Where are Roman numerals still used today?
Roman numerals are commonly used for: clock and watch faces (I through XII), Super Bowl numbering, movie and book sequel numbering, outlines and lists, monarchs and popes (e.g., King Charles III), copyright year notices on films and TV shows, and architectural inscriptions on buildings.
Why is 4 written as IV instead of IIII?
The subtractive notation (IV = 5 - 1 = 4) became the standard convention to avoid having four repeated characters. However, the additive form (IIII) was also used historically and is still seen on many clock faces today. Both forms were used in ancient Rome, but the subtractive form eventually became the accepted standard.