Roman Numeral Converter

Type Arabic numbers (1–3999) on the left, get Roman numerals on the right — or the other way around. One value per line, live as you type. Inline errors for anything out of range or unparseable.

Mode Sync Lock

Arabic 1 – 3999, one per line

Roman i, v, x, … tolerated · spaces between tokens OK

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The 7 Roman symbols

Symbol	Value	Name

The 6 subtractive pairs

A smaller symbol may only sit immediately before the next two symbols up. The pair counts as one of the larger symbol's value.

Pair	Value	Meaning