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Roman Numeral Converter

Convert between numbers and Roman numerals

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About Roman Numeral Converter

Roman Numeral Converter converts between Arabic numbers (1–3999) and Roman numerals instantly and bidirectionally as you type, entirely in your browser.

How to use Roman Numeral Converter

  1. 1Type a number (1–3999) into the Number field, or a Roman numeral into the Roman Numeral field.
  2. 2The opposite field updates automatically as you type — no button needed.
  3. 3Lowercase Roman numerals (e.g., "iv") are accepted and converted to uppercase automatically.
  4. 4Click "Copy Roman Numeral" to copy the Roman numeral result to your clipboard.

Frequently Asked Questions

What's the maximum number this converter handles?

1 to 3,999 (MMMCMXCIX) — standard Roman numerals have no symbol for zero or numbers beyond this range.

Does it validate strict Roman numeral syntax?

No — it calculates a value using standard subtractive/additive rules for any combination of valid letters (I, V, X, L, C, D, M), even unconventional ones like "IIII", so it won't flag historically non-standard combinations as errors.

Can I convert decimals or fractions?

No, only whole numbers convert — Roman numerals don't represent fractional values.

Is Roman Numeral Converter free to use?

Yes, it's completely free with no signup required.

Tips & Tricks

  • ✓Type into either field — the tool detects which direction to convert automatically.
  • ✓The Copy button only copies the Roman numeral value, not the Arabic number — copy the number field's text manually if you need that instead.
  • ✓Lowercase input like "xiv" works fine and converts the same as "XIV".
  • ✓For checking tattoo designs or historical dates, double-check against a reference chart since this tool doesn't flag non-standard letter combinations as invalid.