Convert numbers to and from Roman numerals
Our free Roman numerals converter instantly converts numbers to Roman numerals and Roman numerals back to standard numbers. Perfect for students learning about Roman numerals, designers creating logos, writers formatting documents, and anyone needing this ancient numbering system.
Using our converter is simple. Choose whether you want to convert a number to Roman numerals or Roman numerals to a number by clicking the appropriate button. Enter your value in the input field - use regular numbers (1-3999) for conversion to Roman, or Roman numeral letters (I, V, X, L, C, D, M) for conversion to numbers. Click Convert to see the instant result. The quick reference guide shows the basic Roman numeral values for easy lookup.
Roman numerals originated in ancient Rome and were used throughout the Roman Empire for over 1000 years. Unlike our decimal system which uses place value, Roman numerals use letter combinations where each letter represents a fixed value: I=1, V=5, X=10, L=50, C=100, D=500, and M=1000. Numbers are formed by combining these letters following specific rules. For example, III means 3 (1+1+1), VI means 6 (5+1), and IX means 9 (10-1). The subtractive principle (like IV for 4 and IX for 9) makes the system more compact.
Additive Principle: When a smaller numeral appears after a larger one, you add them. For example, VI = 5+1 = 6, and LX = 50+10 = 60. Letters can be repeated up to three times (III = 3, XXX = 30).
Subtractive Principle: When a smaller numeral appears before a larger one, you subtract it. For example, IV = 5-1 = 4, IX = 10-1 = 9, XL = 50-10 = 40, and XC = 100-10 = 90. This principle prevents repeating a symbol four times.
Order Matters: Roman numerals are written from largest to smallest (left to right), except when using subtraction. MCMXC = 1000+900+90 = 1990. Understanding these rules helps you read and write Roman numerals correctly.
Roman numerals appear frequently in modern life. They're used for copyright dates in movies and TV shows (MMXXIV for 2024). Books use Roman numerals for preface page numbers and chapter numbers in formal publications. Clock faces often display hours in Roman numerals for aesthetic appeal. Sporting events use Roman numerals - Super Bowl LVIII (58), Olympics, and boxing matches. Monarchs and popes use Roman numerals after their names (Queen Elizabeth II, Pope Francis I). Outlines and legal documents use lowercase Roman numerals (i, ii, iii) for subsections. Architectural inscriptions on buildings show construction dates. Pharmaceutical documents use Roman numerals for ingredients and measurements.
Roman numerals dominated European mathematics and record-keeping for over a millennium. The system worked well for addition and subtraction but made multiplication and division challenging. This limitation was one reason why Roman numerals were eventually replaced by Arabic numerals (0-9) in most calculations. However, Roman numerals persist in specific contexts due to tradition, formality, and aesthetic appeal. Understanding Roman numerals connects us to classical history and remains relevant in modern academic, legal, and cultural contexts.
Standard Roman numerals handle numbers from 1 to 3,999 (MMMCMXCIX). The Romans had ways to express larger numbers using bars above numerals (indicating multiplication by 1000), but these aren't standardized in modern usage. Roman numerals have no symbol for zero, which was a significant limitation in mathematics. They're also inefficient for large numbers and complex calculations. This is why our modern decimal system with Arabic numerals became universal for mathematics and science.
All conversions happen instantly in your browser using JavaScript. No data is sent to servers, ensuring complete privacy. The tool works offline and follows standard Roman numeral conventions for accurate conversions in both directions.