Roman Numeral Converter
Convert Arabic numbers to Roman numerals and vice versa with our fast and accurate online tool
Arabic to Roman
Roman to Arabic
What are Roman Numerals?
Roman numerals are a numeral system that originated in ancient Rome and remained the usual way of writing numbers throughout Europe well into the Late Middle Ages. This fascinating numbering system uses combinations of letters from the Latin alphabet to represent different values.
Unlike our modern decimal system, Roman numerals use a subtractive and additive principle. When a smaller numeral appears before a larger one, it is subtracted; when it appears after, it is added. This creates an elegant system that has survived for over two millennia.
Basic Roman Numeral Symbols
| Roman Numeral | Arabic Number | Description |
|---|---|---|
| I | 1 | One |
| V | 5 | Five |
| X | 10 | Ten |
| L | 50 | Fifty |
| C | 100 | One Hundred |
| D | 500 | Five Hundred |
| M | 1000 | One Thousand |
How to Use Our Roman Numeral Converter
Our user-friendly Roman numeral converter makes it easy to convert between Arabic numbers and Roman numerals instantly. Here's how to use this powerful tool:
Converting Arabic Numbers to Roman Numerals
- Enter any number between 1 and 3999 in the Arabic input field
- The Roman numeral equivalent will appear instantly in the result display
- Use the clear button to reset and try a new number
- Perfect for homework, historical research, or decorative purposes
Converting Roman Numerals to Arabic Numbers
- Type Roman numerals in the Roman input field (e.g., XIV, MCMXC)
- The tool automatically converts uppercase and lowercase letters
- See the Arabic number result displayed immediately
- Ideal for reading historical dates, movie credits, or ancient texts
Roman Numeral Rules and Examples
Understanding the rules behind Roman numerals helps you read and write them correctly. Our converter follows these traditional conventions:
Addition Rule
When a smaller numeral follows a larger one, add their values:
- VI = V + I = 5 + 1 = 6
- XII = X + I + I = 10 + 1 + 1 = 12
- LXXX = L + X + X + X = 50 + 10 + 10 + 10 = 80
Subtraction Rule
When a smaller numeral precedes a larger one, subtract the smaller from the larger:
- IV = V - I = 5 - 1 = 4
- IX = X - I = 10 - 1 = 9
- XL = L - X = 50 - 10 = 40
- CD = D - C = 500 - 100 = 400
Common Examples
| Arabic | Roman | Arabic | Roman |
|---|---|---|---|
| 1 | I | 11 | XI |
| 2 | II | 20 | XX |
| 3 | III | 50 | L |
| 4 | IV | 100 | C |
| 5 | V | 500 | D |
| 9 | IX | 1000 | M |
| 10 | X | 2023 | MMXXIII |
Why Use Our Roman Numeral Converter?
Our Roman numeral converter stands out as the most reliable and user-friendly tool available online. Here are the key benefits:
- Instant Results: Get immediate conversions without waiting or page reloads
- Bidirectional Conversion: Convert both ways - Arabic to Roman and Roman to Arabic
- Accurate Algorithm: Based on traditional Roman numeral rules and conventions
- Wide Range Support: Handles numbers from 1 to 3999 (standard Roman numeral range)
- Mobile Friendly: Works perfectly on smartphones, tablets, and desktop computers
- Educational Value: Perfect for students learning about ancient numbering systems
- Professional Quality: Ideal for historians, researchers, and design professionals
- Free to Use: No registration, subscriptions, or hidden fees required
Applications of Roman Numerals Today
Despite being ancient, Roman numerals continue to find practical applications in modern life:
Entertainment and Media
- Movie sequel numbering (Star Wars Episode IV, Rocky II)
- Super Bowl numbering (Super Bowl LVII)
- Book chapter numbering and page numbering
- Video game sequels and versions
Formal and Traditional Uses
- Clock faces and watch designs
- Building cornerstones and architectural elements
- Copyright dates and publication years
- Formal document numbering
- Outline numbering in academic papers