Roman numeral converter
Convert numbers to Roman numerals. Or the other way round.
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Zero, negative numbers, decimals and overbar notation are outside this tool's range. Nonstandard strings such as IIII and IC are rejected instead of guessed. Enter 1 to 3999, or a standard Roman numeral such as MMXXVI. Results update as you type. Up to 1,000,000 characters.
Your result
How to use Roman numeral converter
- Enter number or roman numeral in the input field.
- The result updates as you type. Adjust the available settings if needed.
- Review the result, then use Copy result or a download link when available.
Useful next steps
How to use it
Enter a whole number from 1 to 3,999 or a standard Roman numeral. Both directions work in the same input, including lowercase Roman letters.
A worked example
2026 becomes MMXXVI. XLII becomes 42. Subtractive pairs such as IV, IX, XL and CM are accepted.
What to know
Zero, negative numbers, decimals and overbar notation are outside this tool's range. Nonstandard strings such as IIII and IC are rejected instead of guessed.