Roman Numeral Converter

Convert numbers to Roman numerals and Roman numerals to numbers. Includes reference chart for all values.

Number (1-3999)

Reference Chart

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How to Use the Roman Numeral Converter

Switch between two modes: enter a regular number (1-3999) to convert it to Roman numerals, or enter a Roman numeral to find its numeric value. The converter validates your input and provides instant results. This is helpful for understanding dates on buildings, movie credits, Super Bowl numbers, and historical documents.

Understanding Roman Numerals

Roman numerals originated in ancient Rome and are still used today in various contexts including clock faces, book chapters, movie sequels, and formal documents. The system uses seven basic symbols that combine through addition and subtraction rules to represent numbers. Learning these rules makes it easy to read and write any Roman numeral.

Frequently Asked Questions

What are the basic Roman numeral values?

I=1, V=5, X=10, L=50, C=100, D=500, M=1000. These seven symbols combine to represent any number from 1 to 3999.

How does subtractive notation work?

When a smaller value appears before a larger one, it is subtracted. For example, IV=4 (5-1), IX=9 (10-1), XL=40 (50-10), XC=90 (100-10), CD=400 (500-100), CM=900 (1000-100).

What is the largest number in Roman numerals?

Using standard notation, 3999 (MMMCMXCIX) is the largest. Numbers above 3999 require a bar notation (vinculum) which is less commonly used.

Why do clocks use IIII instead of IV?

Many clock faces use IIII instead of IV for aesthetic balance. With IIII, each quarter of the clock face contains symbols using only I, V, or X, creating visual symmetry.