Roman Numeral Converter
Convert a number (1–3999) into Roman numerals, or a Roman numeral back into a number — it auto-detects which way you're going and validates the input. Calculated in your browser.
- 100% free
- Private & safe
- Runs in your browser
Why use Roman Numeral Converter?
Roman Numeral Converter converts instantly and accurately in your browser, showing every unit or format side by side so you can copy the one you need.
- Runs instantly in your browser — nothing to install, nothing uploaded.
- Completely free, with no account, no watermarks and no usage limits.
- Range: 1–3999
- Type a number or a Roman numeral.
- Works on any device — desktop, tablet and phone — and is fully keyboard accessible.
How to use Roman Numeral Converter
- Type a number or a Roman numeral.
- It detects the direction.
- See the converted value.
- Copy the result.
Examples
- 2026 is MMXXVI.
- Decoding a movie's copyright year.
Supported formats & limits
- Range: 1–3999
Limitations
- Standard Roman numerals only (no vinculum for large numbers).
Frequently asked questions
Why the 3999 limit?
Standard Roman numerals go up to 3999 without special overline notation.
Invalid numerals?
Malformed input like IIII is rejected.
Uploaded?
No — local only.
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