Roman Numeral Converter

Convert between Roman numerals and Arabic numbers instantly. Supports values from 1 to 3,999.

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Roman Numeral
Arabic Number

Roman Numeral Reference Chart

Roman Numeral Arabic Number

Common Examples

Frequently Asked Questions

How do Roman numerals work?
Roman numerals use seven symbols (I, V, X, L, C, D, M) combined additively and subtractively. For example, IV means 5 minus 1 (4), while VI means 5 plus 1 (6).
What is the largest number you can write in Roman numerals?
In standard Roman numeral notation, the largest number is 3,999 (MMMCMXCIX). Numbers above 3,999 require extended notation with overlines.
Why is 4 written as IV instead of IIII?
Roman numerals use subtractive notation where a smaller value before a larger one means subtraction. IV (5 minus 1) is the standard form for 4, keeping numerals concise.
Is this Roman numeral converter free to use?
Yes. This tool is completely free, runs entirely in your browser, and requires no signup. No data is sent to any server.