Roman numeral quiz
Practice converting Arabic numbers to Roman numerals, and vice versa, in quiz mode with instant feedback, or use the free converter to check a specific conversion.
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How it works
Roman numerals use seven basic symbols (I, V, X, L, C, D, M) combined according to additive and subtractive rules: for example IV represents 4 (5 − 1) while VI represents 6 (5 + 1). Quiz mode generates a random number between 1 and 3999 to convert in either direction, while the free converter lets you convert directly in both directions.
Why is the limit set at 3999?
The classical Roman system, with the standard symbols, cannot simply represent numbers above 3999 (MMMCMXCIX) without a special notation such as a bar over the symbol to multiply by 1000. This tool is therefore limited to the usual range of 1 to 3999.
Why are some spellings like "IIII" rejected?
Standard Roman notation favors the subtractive form (IV rather than IIII) to avoid repeating the same symbol more than three times in a row. The converter applies this canonical rule and shows an error if the form entered does not match the standard way of writing a number.
All conversions are calculated locally in JavaScript in your browser, with nothing sent to a server.