Roman Numerals Converter
Convert between Roman numerals and Arabic numbers with detailed explanations
Convert Roman Numerals
Enter any positive integer from 1 to 3,999,999 (extended notation with vinculum for numbers > 3,999)
Quick Examples
Roman Numeral Values
Basic (Standard)
Extended (Vinculum)
Overline (vinculum) = ×1,000
Common Combinations
Roman Numeral Rules
Add when larger comes before smaller (VI = 6)
Subtract when smaller comes before larger (IV = 4)
Only I, X, and C can be subtracted
Only one smaller numeral before larger
Extended: Overline (vinculum) multiplies by 1,000
Understanding Roman Numerals
What are Roman Numerals?
Roman numerals are a numeral system that originated in ancient Rome and remained the usual way of writing numbers throughout Europe well into the Late Middle Ages. They use combinations of letters from the Latin alphabet to signify values.
Key Principles
- •Addition: When a larger numeral comes before a smaller one, add their values (VI = 5 + 1 = 6)
- •Subtraction: When a smaller numeral comes before a larger one, subtract the smaller (IV = 5 - 1 = 4)
- •Repetition: A numeral can be repeated up to three times (III = 3, but not IIII for 4)
- •Vinculum (Extended): An overline multiplies the value by 1,000 (V̅ = 5,000)
Conversion Examples
Example: 2024 → MMXXIV
2024 = 2000 + 20 + 4
2000 → MM (1000 + 1000)
20 → XX (10 + 10)
4 → IV (5 - 1)
Result: MMXXIV
Example: MCMXC → 1990
M = 1000
CM = 900 (1000 - 100)
XC = 90 (100 - 10)
Result: 1000 + 900 + 90 = 1990
Extended: 25,000 → X̅X̅V̅
25,000 = 20,000 + 5,000
20,000 → X̅X̅ (10,000 + 10,000)
5,000 → V̅
Result: X̅X̅V̅
Note: Overline (vinculum) multiplies by 1,000