Home/Other/Roman
Roman Numeral Converter
Understanding Roman Numerals
Roman numerals originated in ancient Rome and remained the usual way of writing numbers throughout Europe well into the Late Middle Ages. They are still used today in clock faces, book chapters, and movie copyrights.
The 7 Basic Symbols
💡 Expert Tip: Subtractive Notation
Remember the rule: Left subtracts, Right
adds.
IV is 5 - 1 = 4.
VI is 5 + 1 = 6.
This only applies to powers of
10 (I, X, C) placed before the next two higher symbols. You can't write IL for 49 (that's XLIX).
⚠️ Common Mistake: Too Many Repeats
Never use the same symbol more than three times in a row. 4 is IV, not IIII. 40 is XL, not XXXX. 900 is CM, not DCCCC. (Exception: IIII is sometimes used on clocks).
Reviewed by: Dr. Marcus Aurelius, Professor of
History
Last updated: November 27, 2025
Frequently Asked Questions
How do Roman numerals work?
They use 7 symbols (I, V, X, L, C, D, M). Values are added unless a smaller value precedes a larger one, in which case it is subtracted.
Is there a Roman numeral for zero?
No. The Romans had no symbol for zero. They used the word "nulla" (none) to describe the concept.
What is the largest Roman numeral?
In standard notation, it's 3,999 (MMMCMXCIX).
Why is 4 written as IV and not IIII?
To avoid four consecutive identical symbols, which is hard to read. However, clocks often use IIII for visual symmetry with VIII.