Roman Numeral Converter
Convert between Arabic numbers and Roman numerals instantly. Perfect for historical dates, clock faces, movie titles, and educational purposes.
Number to Roman Numeral
Valid range: 1 to 3,999
Conversion Breakdown
Roman Numeral to Number
Use standard Roman numerals: I, V, X, L, C, D, M
Roman Numeral Analysis
Roman Numeral Reference
Basic Symbols
Common Combinations
Historical Examples & Common Uses
Historical Dates
Movie Sequels
Clock Faces
How to Use the Roman Numeral Converter
Converting Numbers to Roman
- Enter any number from 1 to 3,999
- The Roman numeral appears instantly
- View the conversion breakdown
- Use quick examples for common numbers
Converting Roman to Numbers
- Type the Roman numeral (case insensitive)
- The Arabic number appears automatically
- Check the symbol-by-symbol analysis
- Use examples to learn common patterns
Roman Numeral Rules & Patterns
Basic Rules
- Addition: When a smaller numeral follows a larger one, add them (VI = 5 + 1 = 6)
- Subtraction: When a smaller numeral precedes a larger one, subtract it (IV = 5 - 1 = 4)
- Repetition: A symbol can be repeated up to 3 times (III = 3, but not IIII)
- Subtraction limits: Only I, X, and C can be subtracted
- Order: Write symbols from largest to smallest value
Advanced Patterns
- Subtractive notation: IV (4), IX (9), XL (40), XC (90), CD (400), CM (900)
- No double subtraction: 8 is VIII, not IIX
- V, L, D never subtracted: Use IV not VL for 45
- Maximum value: Standard Roman numerals go up to 3,999 (MMMCMXCIX)
- No zero: Romans had no symbol for zero
Example Conversions
Number to Roman Examples
1000 = M
900 = CM
90 = XC
4 = IV
Result: MCMXCIV
2000 = MM
20 = XX
4 = IV
Result: MMXXIV
Roman to Number Examples
CD = 400
XL = 40
IV = 4
Result: 444
M = 1000
CD = 400
XL = 40
IV = 4
Result: 1444
Frequently Asked Questions
Why don't Roman numerals go beyond 3,999?
Traditional Roman numerals use overlines or other notation for numbers above 3,999. Our converter uses standard notation which caps at MMMCMXCIX (3,999).
Why is 4 written as IV and not IIII?
While IIII appears on some clock faces, the standard subtractive notation IV is more common and efficient. Both are historically valid.
Can I use lowercase letters?
Yes! Our converter accepts both uppercase and lowercase Roman numerals and automatically converts them to the standard uppercase format.
How do Romans write large numbers?
For numbers above 3,999, Romans used overlines (vinculum) to multiply by 1,000, or different notation systems. Modern usage typically sticks to the 1-3,999 range.