| Symbol | Value | Notes |
|---|---|---|
| I | 1 | Can repeat up to 3× |
| V | 5 | Cannot repeat |
| X | 10 | Can repeat up to 3× |
| L | 50 | Cannot repeat |
| C | 100 | Can repeat up to 3× |
| D | 500 | Cannot repeat |
| M | 1000 | Can repeat up to 3× |
| Combo | Value | Meaning |
|---|---|---|
| IV | 4 | 5 − 1 |
| IX | 9 | 10 − 1 |
| XL | 40 | 50 − 10 |
| XC | 90 | 100 − 10 |
| CD | 400 | 500 − 100 |
| CM | 900 | 1000 − 100 |
Frequently Asked Questions
Standard Roman numerals go up to 3,999 (MMMCMXCIX). Numbers beyond this require extended notation with overlines, which represent multiplication by 1,000. For example, V̄ = 5,000 and M̄ = 1,000,000.
Roman numerals use subtractive notation: placing a smaller numeral before a larger one means subtract it. IV = 5 − 1 = 4. This rule applies for specific pairs: I before V and X, X before L and C, and C before D and M. You may still see IIII on some clock faces — this is called "clock face IV" and was used historically for balance and aesthetics.
The Roman numeral system was developed in ancient Rome and has no symbol for zero or negative values. The concept of zero as a number was introduced by Indian mathematicians centuries later. The system only represents positive integers from 1 to 3,999 in standard form.