Roman Numeral Converter
Convert numbers to Roman numerals and back.
Input
This tool runs entirely in your browser. The data you paste or load is never uploaded.
Result
Enter your input, then run the tool.
About this tool
Converts whole numbers from 1 to 3999 into Roman numerals and reads Roman numerals back into numbers, validating that the numeral is written in standard subtractive form. The direction is detected from what you type.
How to use it
- Type a number such as 2026 or a numeral such as MMXXVI.
- Press Convert.
- Read the result and the breakdown of each symbol.
Frequently asked questions
Why stop at 3999?
Standard Roman numerals have no symbol above M (1000), so 4000 would need four Ms, which breaks the rule of at most three repeats.
Is IIII accepted?
It appears on some clock faces, but the standard form is IV. The tool flags non-standard numerals and shows the correct spelling.
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