Roman Numeral Converter
Convert integers 1-3999 to canonical Roman numerals and validate Roman text with actual token explanations.
Your inputs stay in your browser.Choose the conversion direction explicitly. Numbers 1-3999; Roman input up to 30 ASCII letters. Symbols: I=1 V=5 X=10 L=50 C=100 D=500 M=1000. Subtractive pairs: IV IX XL XC CD CM. Drafts stay in memory only; refreshing clears them. Processing and exports stay local.
Enter values or try an example, then choose Calculate / Generate.
How to use Roman Numeral Converter
Choose Number to Roman or Roman to Number explicitly. Enter the number or ASCII Roman letters, then Calculate. Lowercase and edge whitespace in Roman input are accepted; the original draft stays separate from normalized output.
Worked example
1994 = MCMXCIV = M + CM + XC + IV = 1000 + 900 + 90 + 4. 2026 = MMXXVI.
Rules and limits
I=1, V=5, X=10, L=50, C=100, D=500, M=1000. Only IV, IX, XL, XC, CD and CM are subtractive pairs. Up to 30 entered Roman letters. Reject noncanonical IIII, VV, IL and similar forms, Unicode numeral glyphs, signs, zero, overbars and values above 3999. This is modern conventional notation, not every historical variant.
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