Roman Numeral Converter

Decimal to Roman Numeral

Convert a decimal number to Roman numerals

Decimal Number (1-3999)

Roman Numeral to Decimal

Convert a Roman numeral to a decimal number (enter as a number for each letter value)

Thousands (M=1, MM=2, MMM=3)

Hundreds (1-9, 0 for none)

Tens (1-9, 0 for none)

Ones (1-9, 0 for none)

Formula

Roman numerals: I=1, V=5, X=10, L=50, C=100, D=500, M=1000

Frequently Asked Questions

What are Roman numerals?

Roman numerals are a numeral system from ancient Rome using letters: I=1, V=5, X=10, L=50, C=100, D=500, M=1000. Subtractive notation is used (e.g., IV=4, IX=9).

What is the largest Roman numeral?

Using standard Roman numerals (without vinculum/overlines), the largest representable number is 3,999 (MMMCMXCIX).

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