Roman-Numerals.net
Roman Numeral Converter
Convert Arabic numbers and Roman numerals instantly for the standard range 1–3999. Get a breakdown, neighbors, and shareable results—then explore charts, dates, and a real-world decoder.
Type to convert. Example: 2026 → MMXXVI
Outside 1–3999? See large Roman numerals for extended notation notes. Invalid forms like IIII are rejected and normalized when possible.
How Roman numeral conversion works
Canonical Roman numerals use seven symbols and six subtractive pairs. This converter always returns the standard form—so 4 is IV, not IIII, and 1999 is MCMXCIX.
Symbols
| Symbol | Value |
|---|---|
| I | 1 |
| V | 5 |
| X | 10 |
| L | 50 |
| C | 100 |
| D | 500 |
| M | 1000 |
Subtractive forms
| Form | Value |
|---|---|
| IV | 4 |
| IX | 9 |
| XL | 40 |
| XC | 90 |
| CD | 400 |
| CM | 900 |
Example: 2026 = MMXXVI → M + M + X + X + V + I.
Common Roman Numeral Conversions
A curated set of useful values for learning, tattoos, clocks, and everyday reference—not a claim about search popularity.
Useful Year Conversions
Frequently referenced years with encyclopedia pages and century context.
Learn & practice
Classroom and self-study tools that go beyond quick conversion.
Reference
Rules, history, centuries, and extended notation notes.