Roman Numeral Converter
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Convert numbers to Roman numerals and Roman numerals back to numbers, from 1 to 3999.
In Roman numerals
Roman numeral symbols
- I
- 1
- V
- 5
- X
- 10
- L
- 50
- C
- 100
- D
- 500
- M
- 1,000
About this tool
This tool converts numbers into Roman numerals (2026 → MMXXVI) and Roman numerals back into numbers (XIV → 14). It detects which way to convert from what you type, and checks that Roman numerals are written correctly. Useful for years, book chapters, clock faces, film credits and homework.
How to use
- Type a number from 1 to 3999, or a Roman numeral such as MCMXCIV.
- The conversion appears instantly.
- Copy the result. The table below shows what each symbol is worth.
FAQ
How do Roman numerals work?
Symbols are added from largest to smallest: VI = 5 + 1 = 6. When a smaller symbol comes before a larger one, it is subtracted: IV = 4, IX = 9, XL = 40, XC = 90, CD = 400 and CM = 900.
Why is the limit 3999?
Standard Roman numerals have no symbol above M (1000), and a symbol is not repeated more than three times, so MMMCMXCIX (3999) is the largest. Larger numbers used special notation, such as a bar over a symbol to multiply it by 1000.
Is there a Roman numeral for zero?
No. The Romans had no symbol for zero, so the converter starts at 1.
Why is "IIII" rejected?
The correct form of 4 is IV. Some clock faces use IIII for decoration, but it is not standard, so the tool asks for the correct spelling.