Pro Calculators and Guides
How to Convert Roman Numerals to Numbers and Back (Rules and Examples)
Change 2026 to MMXXVI or MCMXCIV to 1994, with checks for invalid forms such as IIII, and learn the rules.
Saizul Amin15 Oct 2026 · Updated 17 Oct 2026 · 1 min read
Roman numerals still decorate clocks, building dates, book chapters, Super Bowls and film credits. Reading them is easy when you know seven symbols and two rules.
Quick answer
Type a number such as 2026 to get MMXXVI, or a numeral such as MCMXCIV to get 1994. Invalid forms such as IIII are flagged.
The symbols
| Symbol | Value |
|---|---|
| I | 1 |
| V | 5 |
| X | 10 |
| L | 50 |
| C | 100 |
| D | 500 |
| M | 1000 |
The rules
- Add when a smaller symbol follows a larger one: VI = 6, XII = 12.
- Subtract when a smaller symbol comes before a larger one: IV = 4, IX = 9, XL = 40, XC = 90, CD = 400, CM = 900.
- Do not repeat a symbol more than three times in a row.
- Only I, X and C may be placed before a larger symbol to subtract.
Examples
- 1994 = M + CM + XC + IV = MCMXCIV
- 2026 = MM + XX + VI = MMXXVI
- 49 = XL + IX = XLIX (not IL)
Range
Standard numerals cover 1 to 3,999. Larger values use a bar over the symbol to multiply by 1,000.
Steps
- Enter a number or a numeral.
- Read the conversion and any warning.
Uses
Movie years, chapter numbers, clock faces, tattoos, outlines and formal documents.
