Roman Numeral Converter

1. Arabic to Roman: Select the "Arabic to Roman" tab and enter any whole number from 1 to 3,999. The converter instantly displays the Roman numeral equivalent and a visual breakdown showing which symbols make up the number.
2. Roman to Arabic: Select "Roman to Arabic" and type Roman numerals using the letters I, V, X, L, C, D, and M. The converter validates the input and shows the equivalent Arabic number. Invalid combinations (like IIII or VV) are flagged.

Roman numerals use seven letters, each representing a fixed value:

Additive rule: Symbols are generally written from largest to smallest and added together: XII = 10 + 1 + 1 = 12. LXVI = 50 + 10 + 5 + 1 = 66.

Subtractive rule: When a smaller value symbol appears before a larger one, it is subtracted. Six combinations are valid:

• IV = 5 - 1 = 4
• IX = 10 - 1 = 9
• XL = 50 - 10 = 40
• XC = 100 - 10 = 90
• CD = 500 - 100 = 400
• CM = 1000 - 100 = 900

Example: 2024 = MMXXIV

MM    = 2000
XX    = 20
IV    = 4
Total = 2024

Standard Roman numerals have no symbol for zero and cannot represent numbers above 3,999 without extensions (like a bar over a symbol to multiply by 1,000).