Roman Numerals Calculator
Convert Arabic numbers to Roman numerals and back
Roman Numerals - Converter and Calculator Online
Our free Roman numerals converter lets you switch quickly between Arabic (1, 2, 3...) and Roman (I, II, III...). Enter an Arabic or Roman number and the calculator converts it. It supports numbers from 1 to 3999.
The 7 basic symbols
| Symbol | Value |
|---|---|
| I | 1 |
| V | 5 |
| X | 10 |
| L | 50 |
| C | 100 |
| D | 500 |
| M | 1000 |
How does subtractive notation work?
When a smaller symbol appears before a larger one, we subtract its value. For example: IV = 5-1 = 4, IX = 10-1 = 9, XL = 50-10 = 40, XC = 100-10 = 90, CD = 500-100 = 400, CM = 1000-100 = 900.
Where are Roman numerals used today?
- Clocks - Clock faces often use Roman numerals
- Book chapters - Chapter and volume numbering
- Dates - Years on buildings, films (e.g. MMXXVI = 2026)
- Monarchs and popes - Elizabeth II, John Paul II
- Events - Super Bowl LVIII, Olympic Games XXXIII
Frequently asked questions
Why is the maximum 3999?
In the standard system there is no symbol for 5000. Larger numbers need special notation (e.g. vinculum = ×1000).
Is 4 written as IIII or IV?
Both are correct. IV (subtractive) is more common, but IIII appears on many clocks.
Is there a symbol for zero?
No. The Romans did not have a concept of zero as a number. Their system was additive and did not need a symbol for nothing.