Roman Numeral Converter
Convert a number to its Roman numeral form, or decode a Roman numeral back to a number.
Overview
Roman numerals use subtractive notation for certain values (IV for 4, not IIII; IX for 9, not VIIII), which makes both directions of conversion easy to get subtly wrong by hand. This tool applies the standard rules, including strict validation on decoding — a malformed sequence like "IIII" or "VX" is rejected rather than silently misread.
Examples & Sample Data
Number to Roman
1994
MCMXCIV
Roman to number
MCMXCIV
1994
How It Works
- Choose a direction: Number → Roman or Roman → Number.
- Enter the value.
- The converted result appears instantly.
Common Use Cases
Reading dates and credits
Decode a Roman numeral year from a film's copyright notice or a monument's inscription.
Outline and chapter numbering
Convert a chapter or section number to Roman numeral style for formal documents.
Tips & Best Practices
- Roman numerals only represent whole numbers from 1 to 3999 — there's no standard Roman numeral for zero or negative numbers, and numbers above 3999 need notation conventions this tool doesn't cover.
Frequently Asked Questions
No. Every conversion runs locally in your browser.
The decoder only accepts valid, correctly-formed Roman numerals — repeated subtractive pairs, more than three repeated symbols in a row (like IIII), and out-of-order combinations are all invalid Roman numeral notation, not just unusual formatting.
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