Why can't I convert 0 or negative numbers?

The Roman numeral system has no symbol for zero and no concept of negative numbers — it was designed for counting and accounting, not signed arithmetic. Only whole numbers from 1 to 3999 can be represented in standard notation.

Why is 1999 written as MCMXCIV-style subtractive notation instead of MDCCCCLXXXXVIIII?

This converter uses standard subtractive notation, where a smaller symbol placed before a larger one is subtracted (like CM for 900, XC for 90). This is the widely accepted modern convention; a purely additive form is historically valid but far less common today.

Roman Numeral Converter

Convert numbers to Roman numerals and back.

How this is calculated

Greedy subtraction of the largest value/symbol pairs (M, CM, D, CD, C, XC, L, XL, X, IX, V, IV, I)

Assumptions used in this calculation

Range: Standard Roman numerals only represent 1 to 3999.

About this calculator

The Roman numeral converter converts numbers (1-3999) to Roman numerals and Roman numerals back to numbers, using standard subtractive notation.

Worked example

1994

Result: MCMXCIV

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Frequently asked questions

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Roman Numeral Converter

About this calculator

Frequently asked questions

Why can't I convert 0 or negative numbers?

Why is 1999 written as MCMXCIV-style subtractive notation instead of MDCCCCLXXXXVIIII?

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