Roman Numeral Converter
Convert between decimal and Roman numerals
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Please enter an integer between 1 and 3999.
Reference Table
How to Use Roman Numeral Converter
- 1Select the conversion direction: Decimal to Roman or Roman to Decimal.
- 2Enter the number or Roman numeral in the input field.
- 3The conversion appears instantly as you type.
- 4Copy the result using the Copy button.
About Roman Numeral Converter
Convert between decimal numbers and Roman numerals instantly. Supports numbers from 1 to 3,999. Validates Roman numeral syntax and detects invalid input. Includes a reference table of Roman numeral symbols and their values.
Frequently Asked Questions
What numbers can be converted?
Standard Roman numerals represent numbers from 1 to 3,999. The number 4,000 and above require special notation (bars over letters) which is not part of the standard system.
What are the basic Roman numeral symbols?
I=1, V=5, X=10, L=50, C=100, D=500, M=1000. Subtractive notation is used: IV=4, IX=9, XL=40, XC=90, CD=400, CM=900.
Is the Roman numeral validation strict?
Yes. The converter validates that the Roman numeral follows standard rules — no more than three consecutive same symbols, proper subtractive notation, and valid characters only.