FREE
Roman numeral converter
Convert whole numbers 1–3999 to Roman numerals and back locally.
Explore toolsRoman numeral converter
Convert whole numbers 1–3999 to Roman numerals and back locally.
How to use
- Conversion direction
- Value to convert
- Convert
Standard Roman numerals and whole numbers from 1 to 3999
Choose a direction and enter the value to convert. This tool supports only positive whole numbers 1–3999 and standard Roman numerals I–MMMCMXCIX; it does not cover every historical notation variant. Zero, negative numbers, fractions, signs and overline notation are unsupported. Number input accepts only ASCII digits 0–9; leading zeros are allowed: 0026 → XXVI. Roman input accepts the ASCII letters I, V, X, L, C, D and M in either case; leading and trailing whitespace is trimmed. Only standard notation with the subtractive pairs IV, IX, XL, XC, CD and CM is accepted; IIII, IL, IC, VV, IIV and MMMM are rejected. Unicode Roman numeral symbols are unsupported. Raw input, including whitespace, is limited to 100 characters. Conversion runs locally in your browser; input is not sent to a server. Changing the input or direction invalidates the previous result. Clear removes input and output and restores the number-to-Roman direction.
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Example
2026
MMXXVI
Frequently asked questions
Is my input sent to a server?
Your images, text, QR contents and calculations are processed in your browser. Read our privacy policy for details about hosting, local storage and the current advertising status.
Is this tool free?
No account needed · Always free