Roman Numeral Converter

How to Use the Roman Numeral Converter

Simply enter a number or a Roman numeral. Click convert and check the result, with step-by-step breakdowns.

What Are Roman Numerals?

Roman numerals are symbols from ancient Rome used to write numbers. They use letters like I, V, X, L, C, D, and M to represent values. For example, I = 1, V = 5, X = 10, and so on.

Number to Roman Numeral Conversion Formula

To convert a number into Roman numerals, we match the largest possible Roman symbol to the value repeatedly:

• 1000 = M
• 900 = CM
• 500 = D
• 400 = CD
• 100 = C
• ... down to 1 = I

Example: 1987 = M (1000) + CM (900) + L (50) + XXX (30) + VII (7) → MCMLXXXVII

Roman Numeral to Number Formula

Start from left to right. If a smaller value is before a larger one, subtract it. Otherwise, add normally.

Example: IX = 10 − 1 = 9, while XI = 10 + 1 = 11.

Common Uses of Roman Numerals

• Clock faces and watches
• Movie sequels (e.g., Rocky IV)
• Book chapters and outlines
• Historical dates and monuments