Roman Numeral Converter
Convert between Roman numerals and decimal numbers instantly
Roman Numeral Converter
Conversion Rules
Basic Symbols
| Symbol | Value |
|---|---|
| I | 1 |
| V | 5 |
| X | 10 |
| L | 50 |
| C | 100 |
| D | 500 |
| M | 1000 |
Subtractive Notation
| Symbol | Value |
|---|---|
| IV | 4 |
| IX | 9 |
| XL | 40 |
| XC | 90 |
| CD | 400 |
| CM | 900 |
Conversion History
No conversions yet. Start typing to see history.
Common Roman Numerals
| Decimal | Roman |
|---|---|
| 1 | I |
| 5 | V |
| 10 | X |
| 50 | L |
| 100 | C |
| 500 | D |
| 1000 | M |
| 2024 | MMXXIV |
| 2025 | MMXXV |
| 2026 | MMXXVI |
Usage Examples
Current Year
Convert the current year 2026 to its Roman numeral representation MMXXVI.
Historic Date
Decode MCMLXXXIV (1984) - commonly seen in movie credits and copyright notices.
Maximum Value
See the largest Roman numeral: 3999 = MMMCMXCIX, the maximum in standard notation.
Features
Real-Time Conversion
Both fields update instantly as you type, with immediate validation feedback
Bidirectional
Type a Roman numeral or a decimal number - both directions work seamlessly
Conversion History
Tracks your last 10 conversions for easy reference and comparison
Privacy First
All conversions happen locally in your browser, no data sent to servers
How to Use?
Enter a Value
Type a Roman numeral (e.g., MMXXVI) or a decimal number (e.g., 2026) in either field.
See Instant Result
The other field updates automatically with the converted value as you type.
Copy or View History
Copy the result with one click. View your last 10 conversions in the history panel.
Frequently Asked Questions
What Is a Roman Numeral Converter?
It's a quick way to translate between Roman numerals (like XIV or MMXXVI) and regular numbers. You type one, you get the other. Handy when you run into Roman numerals on clocks, in book chapters, movie credits, or anywhere else they pop up.
Key Features
The converter works in both directions and updates as you type. It validates your input in real time, keeps a history of your last 10 conversions, and includes a reference table of common numerals. One-click copy makes it easy to grab results.
Common Use Cases
Students use it for homework, designers need it for typography, and history buffs run into Roman numerals constantly. It's also great for decoding copyright years in movie credits or figuring out what year that building cornerstone says.
Tips for Working with Roman Numerals
Remember the seven symbols: I, V, X, L, C, D, and M. When a smaller value appears before a larger one, subtract it (IV = 4). The maximum in standard notation is 3999 (MMMCMXCIX).
Privacy
All conversions happen right in your browser using JavaScript. Nothing gets sent to a server, so your data stays completely private.
Roman Numerals Complete Guide: How to Read, Write & Convert Them
Learn the 7 Roman numeral symbols, the additive and subtractive rules, and how to convert any number step by step. Includes reference tables for 1–20 and real-world uses on clocks, Super Bowl logos, movie sequels, and more.