Roman Numerals to Number
Convert Roman numerals to numbers easily. Free Roman numeral to number converter.
Decimal Number
42
Basic Roman Numerals
| Roman Numeral | Decimal Value |
|---|---|
| I | 1 |
| V | 5 |
| X | 10 |
| L | 50 |
| C | 100 |
| D | 500 |
| M | 1000 |
Subtractive Combinations
When a smaller numeral appears before a larger one, it is subtracted:
| Roman Numeral | Decimal Value |
|---|---|
| IV | 4 |
| IX | 9 |
| XL | 40 |
| XC | 90 |
| CD | 400 |
| CM | 900 |
How to Convert Roman Numerals to Numbers
Add up symbol values, but subtract when a smaller symbol precedes a larger one. So MCMXC: M=1000, C before M means -100, M=1000, X before C means -10, so 1000 + (1000-100) + (100-10) = 1000 + 900 + 90 = 1990.
Useful for reading old building dates, movie sequel numbers, or pope/monarch designations. Roman numerals appear on copyright dates (MCMXC = 1990), Super Bowl events, dynasty names. The conversion isn't always linear - subtractive pairs (IV, IX, XL, XC, CD, CM) need careful reading.
Common Roman Numerals to Numbers
| Roman Numeral | Number |
|---|---|
| I | 1 |
| X | 10 |
| L | 50 |
| C | 100 |
| MCM | 1900 |
| MMXX | 2020 |
| MMXXIV | 2024 |
| MMMCMXCIX | 3999 |
Frequently Asked Questions
What's the maximum?
Standard form: 3999 = MMMCMXCIX. Above this, no single accepted notation - some use 'MΜ' (M with overbar) for 1000Γ1000, but this isn't standard. For numbers above 3999, modern usage typically reverts to Arabic numerals.
Are Roman numerals still used in legal contexts?
Yes - some legal documents, book chapter numbering, and outline numbering use Roman numerals. Court cases sometimes use 'I, II, III...' for numbered defendants. Religious texts use Roman numerals for chapter and verse references.