Roman Numerals Converter
The Roman numerals converter lets you instantly convert between Arabic numbers (1–3999) and Roman numerals. Enter a number to get its Roman representation, or type Roman numerals to find the Arabic value.
Roman numerals are still widely used in clocks, book chapters, movie sequels, outlines, and formal documents. This tool validates input and handles subtractive notation (IV, IX, XL, XC, CD, CM) correctly.
How it works
Roman numerals use seven symbols: I=1, V=5, X=10, L=50, C=100, D=500, M=1000. When a smaller symbol precedes a larger one, it is subtracted (e.g., IV=4, IX=9). Otherwise symbols are added left to right. Valid range is 1–3999.
Use cases
- Converting years to Roman numerals for formal documents or inscriptions
- Decoding Roman numerals on clocks, buildings, or monuments
- Numbering chapters, sections, or outlines in academic writing
- Understanding movie sequel numbering and Super Bowl editions
Frequently asked questions
How do you write 2024 in Roman numerals?
2024 is written as MMXXIV. It breaks down as MM for 2000, XX for 20, and IV for 4 (which uses subtractive notation, one before five). Reading left to right and adding each group gives 2000 + 20 + 4 = 2024.
What are the seven Roman numeral symbols?
Roman numerals use seven letters: I = 1, V = 5, X = 10, L = 50, C = 100, D = 500, and M = 1000. All other numbers are built by combining these symbols through addition or subtractive notation. For example, C + X + I gives 111 (CXI).
What is the largest number you can write in Roman numerals?
Using standard notation the largest value is 3999, written as MMMCMXCIX. That is the practical limit because there is no single symbol for 5000, so four Ms (4000) would be needed, which classical rules avoid. Larger numbers historically used a bar over a numeral to multiply it by 1000.
How does subtractive notation work in Roman numerals?
When a smaller symbol appears immediately before a larger one, its value is subtracted rather than added. The six valid pairs are IV (4), IX (9), XL (40), XC (90), CD (400), and CM (900). This avoids writing four identical symbols in a row, so 4 is IV instead of IIII.
Is there a Roman numeral for zero?
No. The Roman numeral system has no symbol for zero because it was designed for counting and commerce, where a value of nothing was simply not written. The concept of zero as a numeral came later through Indian and Arabic mathematics. That is also why the valid range for this converter starts at 1.