Roman Numeral Converter

Convert a whole number to Roman numerals or decode a standard Roman numeral. Supports 1–3999 and checks canonical subtractive notation.

Convert a modern year

Enter 2026 to obtain MMXXVI. Thousands, tens and units are assembled with the conventional Roman symbols.

IV means four and IX means nine. Similar pairs include XL, XC, CD and CM.

Forms such as IIII and IC are rejected. The decoder compares the result with canonical notation to prevent accepting malformed sequences.

This converter handles numbers through 3999 without overlines or medieval variants. Zero and negative values have no output here.

Can I enter lowercase mmxxvi?

Yes. Letter input is normalized to uppercase before checking its notation.

What is 49 in Roman numerals?

49 is XLIX: XL contributes forty and IX contributes nine.