Romertallkonverterer

What Is a Roman Numeral Converter?

A Roman numeral converter translates between standard Arabic integers and Roman numeral notation (I, V, X, L, C, D, M). Roman numerals appear in book chapters, clock faces, movie sequels, legal documents, and historical inscriptions.

This tool handles both directions — converting a number you want to display in Roman form, or decoding a Roman numeral you've encountered in a text.

How to Convert to/from Roman Numerals

1. Select whether converting to or from Roman numerals
2. Enter either a decimal number or Roman numeral
3. View the conversion instantly
4. Copy the result for use in documents or designs

Features

• Convert decimal numbers to Roman numerals and vice versa
• Support for both standard and vinculum (overline) notation for large numbers
• Handles numbers from 1 to 3,999,999
• Useful for historical dates, outlines, and formal documents

Common Use Cases

• Writing chapter or section numbers in Roman numerals for books or outlines
• Decoding copyright year notices written in Roman numerals on films or broadcasts
• Designing clock faces, logo engraving, or formal event invitations

Why Use ToolPop Roman Numeral Converter

• Handles both Arabic-to-Roman and Roman-to-Arabic conversion in one tool
• Supports the full standard range up to 3999 (MMMCMXCIX)
• Useful for typography, publishing, clock design, and historical research

ToolPop vs Manual Conversion

Decoding Roman numerals with subtractive notation (IV = 4, IX = 9, XL = 40) is easy to get wrong, especially for larger numbers. ToolPop follows the standard rules precisely and handles edge cases correctly, so you get the right result without counting on your fingers.

Tips

• Roman numerals use I=1, V=5, X=10, L=50, C=100, D=500, M=1000
• A line (vinculum) over a numeral multiplies it by 1,000
• Subtractive notation (like IV for 4) follows specific rules

Frequently Asked Questions

Why is 4 written as IV and not IIII?

Subtractive notation puts a smaller value before a larger one to indicate subtraction. IV (5-1=4) is standard, though IIII appears on some clock faces for symmetry.

How do you represent numbers larger than 3,000?

A vinculum (horizontal line) above a numeral multiplies it by 1,000. For example, V with a line over it represents 5,000.

Is my conversion kept confidential?

Absolutely. All Roman numeral conversions happen locally in your browser—no data is collected or transmitted.