Roman Numeral Converter

Roman Numeral Converter

Convert between Arabic numbers and Roman numerals, review the breakdown, and keep a small history of recent results.

Last updated: June 2026 | By Patchworkr Team

Quick Examples
Conversion Output

Roman numeral result

Enter a value to convert

What are Roman Numerals?

Roman numerals are an ancient number system built from the symbols I, V, X, L, C, D, and M. They use both additive and subtractive notation, which is why values like IV and IX mean 4 and 9.

They still show up in clocks, chapter headings, anniversaries, and formal numbering. This converter handles the standard range from 1 to 3999.

Roman Numeral Reference

I
1
V
5
X
10
L
50
C
100
D
500
M
1000
IV= 4
IX= 9
XL= 40
XC= 90
CD= 400
CM= 900

FAQ

Why does the converter limit values to 3999?

That is the standard Roman numeral range used by most modern tools and references.

Why reject repeated symbols like IIII?

Standard Roman numerals limit repetition so the notation stays readable and unambiguous.

Does the breakdown work for both directions?

The breakdown is most useful for Roman numerals, but the converter still shows the conversion output in either mode.

Can I reuse a history entry?

Yes. Clicking an item in the history panel loads it back into the converter.

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