Roman numeral converter
Convert numbers to Roman numerals and Roman numerals back to numbers.
🔒 Everything runs in your browser. Nothing you choose or type is uploaded. How to verify
How to use it
- Type a number from 1 to 3999 or a Roman numeral.
- Read the result, which updates as you type.
- Copy it where you need it.
Handy for
Writing years on monuments, film credits, clocks and book chapters.
Good to know
I is 1, V is 5, X is 10, L is 50, C is 100, D is 500 and M is 1000. A smaller symbol before a larger one is subtracted, as in IX for 9.
Privacy: where the work happens
Everything you enter or choose is processed by JavaScript in your browser and never sent anywhere. Only the page code, and any library this tool needs, is downloaded from cdnjs or jsDelivr.
Questions
Why is the limit 3999?
Standard Roman numerals have no symbol above M for a thousand, so 3999 (MMMCMXCIX) is the usual maximum.
Is IIII valid?
Clocks sometimes use it, but standard form writes four as IV, and the tool expects the standard form.