Roman Numeral Converter
Arabic ↔ Roman · Both directions
Arabic Number
⇄
Roman Numerals
Step-by-Step Breakdown
Roman Numeral Reference — click any to convert
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Roman Numerals Explained
What are the basic Roman numeral symbols?+
The seven symbols: I = 1, V = 5, X = 10, L = 50, C = 100, D = 500, M = 1000. All other numbers are formed by combining these. The mnemonic "I Value Xylophones Like Cows Do Milk" helps remember the order.
How does subtraction work in Roman numerals?+
When a smaller symbol appears before a larger one, it is subtracted. The six subtractive combinations are: IV = 4, IX = 9, XL = 40, XC = 90, CD = 400, CM = 900. Only these specific combinations are valid — you cannot write IC for 99 (must be XCIX) or VX for 5 (invalid).
Where are Roman numerals used today?+
Roman numerals appear on clock faces, in book chapter numbering, movie sequel titles (Rocky II, Star Wars Episode IV), Olympic Games years, Super Bowl numbers, monarchs and popes (King Charles III, Pope John Paul II), building construction dates, and copyright years in film credits.
What is the largest Roman numeral?+
Using standard notation, the largest is MMMCMXCIX = 3,999. Romans handled larger numbers using a bar over a letter (vinculum) to multiply by 1,000 — so V̄ = 5,000 and M̄ = 1,000,000. Our converter supports this extended range up to 3,999,999 using parentheses notation.