Roman Numeral
Roman Numeral Reference
| Roman | Arabic | Note |
|---|---|---|
| I | 1 | – |
| IV | 4 | Subtractive |
| V | 5 | – |
| IX | 9 | Subtractive |
| X | 10 | – |
| XL | 40 | Subtractive |
| L | 50 | – |
| XC | 90 | Subtractive |
| C | 100 | – |
| CD | 400 | Subtractive |
| D | 500 | – |
| CM | 900 | Subtractive |
| M | 1000 | – |
What is a Roman Numeral Converter?
Roman Numeral Converter turns Arabic numbers such as 42 or 2024 into Roman numerals like XLII and MMXXIV, and it also works in reverse. It is useful for documents, clocks, chapter headings, and historical references.
How to Use Roman Numeral Converter
- Choose whether you want number-to-Roman or Roman-to-number conversion.
- Enter the value into the input field.
- Read the converted output instantly.
- Copy the result when you need it in a document, design, or worksheet.
Understand Roman Numeral Converter ▾
Example
Input
Arabic → Roman: 2024 → MMXXIV
Output
Roman → Arabic: XIV → 14 , MCMXCIX → 1999
Common Use Cases
- Convert chapter, outline, and section numbers into Roman numerals
- Interpret dates or clocks that use Roman numeral notation
- Verify subtractive forms like IV, IX, XL, and CM
- Teach Roman numeral rules with instant two-way conversion
Roman Numeral Rules
Symbols: I=1, V=5, X=10, L=50, C=100, D=500, M=1000.
Subtractive notation is used for IV, IX, XL, XC, CD, and CM. Standard modern usage typically covers values from 1 to 3999.
Why Use This Tool
- Handles subtractive notation correctly without manual lookup.
- Useful for publishing, education, history references, and decorative numbering.
- Supports both directions so you can verify unfamiliar numerals quickly.
Frequently Asked Questions
What is the largest number supported?
3999 (MMMCMXCIX). Roman numerals have no standard representation for 4000+.
Are lowercase Roman numerals accepted?
Yes — both uppercase (XIV) and lowercase (xiv) input are accepted.
What does Roman Numeral Converter Online – Numbers to Roman & Back do?
Roman Numeral Converter Online – Numbers to Roman & Back runs entirely in your browser and helps you complete this task without uploading data to a server.
Is Roman Numeral Converter Online – Numbers to Roman & Back free to use?
Yes. This tool is free to use and does not require sign-up.