Roman Numeral Converter
Convert Roman numerals to numbers and convert numbers to Roman numerals.
How to Use This Roman Numeral Converter
- Enter a decimal number (1-3999) or a Roman numeral in the input field.
- Select the conversion direction: decimal to Roman or Roman to decimal.
- The converted result appears instantly below the input.
- Copy the result using the copy button for use in your documents.
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 (I, V, X, L, C, D, M) to represent values.
Supported Range
This converter supports numbers from 1 to 3999. Common uses include clock faces, chapter numbering, copyright years, and Super Bowl numbering.
Features
- Convert decimal numbers to Roman numerals and vice versa
- Support for numbers from 1 to 3999
- Input validation with helpful error messages
- Real-time conversion as you type
- Quick reference for Roman numeral symbols and values
Use Cases
- Adding Roman numeral chapter numbers to documents and books
- Converting copyright year notices to Roman numeral format
- Decoding Roman numerals found on clock faces or monuments
- Formatting outline numbering in academic and legal documents
- Learning and practicing Roman numeral conversions
Frequently Asked Questions
Why is the maximum number 3999?
Standard Roman numerals use symbols up to M (1000). The largest number representable without extended notation is MMMCMXCIX (3999). Numbers above 3999 require vinculum notation, which uses bars over letters to multiply by 1000.
How does subtractive notation work?
When a smaller numeral appears before a larger one, it is subtracted. For example, IV means 5 minus 1 (4), and XC means 100 minus 10 (90). Only I, X, and C can be used subtractively.
Is there a Roman numeral for zero?
No. The Roman numeral system does not have a symbol for zero. The concept of zero was introduced to Europe later through the Hindu-Arabic numeral system. This is one reason Roman numerals were eventually replaced.