Roman Numeral Converter
Convert between Arabic numbers (1–3999) and Roman numerals instantly.
Range: 1 – 3999
Enter uppercase or lowercase
The Roman Numeral Converter translates integers between the familiar decimal system and classical Roman notation. Type an Arabic number to get its Roman equivalent, or type Roman numerals to decode them — conversion happens in real time with instant feedback.
Frequently Asked Questions
Why is the range limited to 1–3999? +
Standard Roman notation (using I, V, X, L, C, D, M) represents numbers up to 3999 without requiring overline or vinculum notation for large numbers. Numbers above 3999 need extended notation not covered here.
What is subtractive notation? +
When a smaller numeral precedes a larger one (e.g. IV = 4, CM = 900), the smaller value is subtracted from the larger. This is the standard modern convention and is fully supported here.
Is Roman numeral input case-sensitive? +
No — you can type Roman numerals in lowercase or uppercase. The tool normalizes them to uppercase internally before converting.
Frequently Asked Questions
- Symbols are added left to right: 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: IV=4, IX=9, XL=40, XC=90, CD=400, CM=900.