Roman Numeral Converter
Convert between Roman numerals and Arabic numbers. Supports values from 1 to 3,999 with instant bidirectional conversion.
About This Free Online Roman Numeral Converter
Our free online Roman numeral converter instantly converts between Roman numerals and Arabic (decimal) numbers. Type a number like 2024 to get MMXXIV, or paste Roman numerals like MCMXCVIII to get 1998. Supports all standard Roman numeral combinations from 1 to 3,999. Perfect for students learning Roman numerals, historians, clock enthusiasts, and anyone dealing with Roman numeral dates or references.
Features of Our Roman Numeral Converter
- Convert Arabic numbers to Roman numerals
- Convert Roman numerals to Arabic numbers
- Supports values from 1 to 3,999
- Auto-detection — type number or Roman numeral
- Real-time conversion as you type
- Copy result to clipboard
- 100% private — browser-only processing
How to Use the Roman Numeral Converter
Using this tool is simple and requires no signup or registration. Follow these steps:
- Type a number (like 2024) or Roman numeral (like MMXXIV) into the input area.
- The tool auto-detects which direction to convert.
- The converted result appears instantly below.
- Click Copy to save the result to your clipboard.
Frequently Asked Questions About Roman Numeral Converter
What is the largest Roman numeral supported?
The tool supports Roman numerals up to 3,999 (MMMCMXCIX). Larger numbers require special notation (like a vinculum/bar over letters for ×1,000) which is not standard in basic Roman numeral systems.
How do Roman numerals work?
Roman numerals use seven letters: I=1, V=5, X=10, L=50, C=100, D=500, M=1,000. Numbers are formed by combining letters, with smaller values before larger values indicating subtraction (IV=4, IX=9, XL=40, XC=90, CD=400, CM=900).
Why is 4 written as IV instead of IIII?
Roman numerals use subtractive notation: I before V (5) means 5-1=4. This is the standard form used today. However, IIII was commonly used in ancient Rome and still appears on some clock faces.
Why Choose Text Toolbox?
Text Toolbox provides free, private, and instant online text tools. Unlike other text utility websites that require signup accounts or send your data to servers, all our tools process your text entirely in your browser. This means your content never leaves your device — we cannot see it, store it, or share it. Our tools are fast, lightweight, and work on any device with a modern web browser.