Roman Numeral Values
| Symbol | Value | Symbol | Value |
|---|---|---|---|
| I | 1 | C | 100 |
| V | 5 | D | 500 |
| X | 10 | M | 1,000 |
| L | 50 |
Subtractive Pairs
| Combination | Value | Instead of |
|---|---|---|
| IV | 4 | IIII |
| IX | 9 | VIIII |
| XL | 40 | XXXX |
| XC | 90 | LXXXX |
| CD | 400 | CCCC |
| CM | 900 | DCCCC |
Roman Numeral Converter
Convert between decimal numbers and Roman numerals. Supports 1 to 3,999.
Decimal → Roman
Roman → Decimal
📐 How We Calculate — Learn about our calculation methodology, data sources, and quality standards.
Frequently Asked Questions
How do Roman numerals work?
I=1, V=5, X=10, L=50, C=100, D=500, M=1000. Place smaller before larger to subtract (IV=4, IX=9).
What is the largest Roman numeral?
Standard notation goes to 3,999 (MMMCMXCIX). A bar over a letter multiplies by 1,000 for larger numbers.
Why is 4 written as IV, not IIII?
IV (subtractive) is the modern standard, but IIII was also used in ancient Rome and appears on many clock faces.