Roman Numeral Converter

Convert standard Roman numerals both ways and catch invalid forms such as IC or repeated V.

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Use integers from 1 to 3999 or standard Roman numerals using I, V, X, L, C, D, and M.

Supported range: 1 to 3999 with standard subtractive notation.

Roman Numeral Converter

Supported range: 1 to 3999 with standard subtractive notation.

Result

Roman numeral table

I1
V5
X10
L50
C100
D500
M1000

FAQ

What range is supported?

This converter supports standard Roman numerals for integers from 1 to 3999.

Why is IC invalid for 99?

Standard notation uses XCIX for 99. I can subtract only from V or X, so IC is rejected.

Are overlines for 5000 and larger supported?

No. This page keeps the common school and reference range of 1 to 3999.