Roman Numeral Converter guide
Roman Numeral Converter: Numbers to Roman Numerals and Back
Use our Roman numeral converter to turn any number from 1 to 3,999 into Roman numerals, or convert Roman numerals back to numbers.
By the AllCalculator editorial teamUpdated 16 October 20261 min read
Roman numerals still appear on clock faces, film credits, book chapters and monarchs' names. Our Roman Numeral Converter converts both ways.
How to use the calculator (Roman Numeral Converter)
Type a number from 1 to 3,999, or type Roman numerals like MCMXCIV. The calculator works out which you've entered and converts it.
The symbols
| Symbol | Value |
|---|---|
| I | 1 |
| V | 5 |
| X | 10 |
| L | 50 |
| C | 100 |
| D | 500 |
| M | 1,000 |
The rules
- Symbols are usually written from largest to smallest and added: VIII = 5 + 3 = 8.
- A smaller symbol before a larger one is subtracted: IV = 4, IX = 9, XL = 40, XC = 90, CD = 400, CM = 900.
- A symbol isn't repeated more than three times in a row.
Worked examples
- With the calculator's default settings, 2026 = MM (2,000) + XX (20) + VI (6) = MMXXVI.
- MCMXCIV = M (1,000) + CM (900) + XC (90) + IV (4) = 1994.
Frequently asked questions
Why do some clocks show IIII instead of IV?
It's a long tradition in clockmaking, possibly for visual balance with VIII on the other side. The calculator reads IIII as 4 but tells you it's not standard form.
Is there a Roman numeral for zero?
No. The Romans didn't have a symbol for zero.
How do you write numbers above 3,999?
Traditionally with a bar over a numeral to multiply it by 1,000, which isn't standard in everyday use.
Sources and further reading
Links open official and independent websites in a new tab.
This guide is general information to help you understand your options. It isn't financial, tax, legal or building advice and doesn't take your personal circumstances into account. Figures were checked when the guide was last updated and can change, so confirm anything important with GOV.UK, HMRC, a regulated adviser or a qualified tradesperson.