Roman Numeral Converter

Number to Roman Numeral

Enter a number between 1 and 3,999,999 to convert to Roman numerals.

Enter Number:

Use the arrows or type directly. For large numbers, use the random button for examples.

Roman Numeral Result:

MMXXIV

Roman Numeral to Number

Enter a valid Roman numeral (I, V, X, L, C, D, M) to convert to a number.

Enter Roman Numeral:

Use uppercase letters: I, V, X, L, C, D, M. For numbers above 3,999, we use Vinculum notation.

Number Result:

2024

Roman Numeral Reference

Vinculum Notation: For numbers above 3,999, a line over a numeral multiplies it by 1,000 (e.g., V̅ = 5,000, X̅ = 10,000).

Conversion History

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User Guide on Roman Numeral Converter

Converting Numbers to Roman Numerals

1. Enter a number between 1 and 3,999,999 in the "Number to Roman Numeral" input field.

2. Click the "Convert to Roman" button or press Enter to generate the Roman numeral.

3. The Roman numeral will appear in the result box below the input.

4. Use the "Copy Roman" button to copy the result to your clipboard.

5. For large numbers (above 3,999), the converter uses Vinculum notation with overlines.

Converting Roman Numerals to Numbers

1. Enter a Roman numeral in the "Roman Numeral to Number" input field.

2. Use uppercase letters: I, V, X, L, C, D, M.

3. Click "Convert to Number" to decode the Roman numeral.

4. The numeric value will appear in the result box.

5. Use the "Copy Number" button to copy the result to your clipboard.

Downloading Conversions

1. After performing conversions, click the "Download Conversion" button.

2. A text file will be generated containing your input and conversion results.

3. The file includes a timestamp and the Roman numeral reference table.

4. You can save this file for your records or share it with others.

Additional Features

1. Random Number: Use the "Random" button to generate and convert a random number.

2. History: View your recent conversions in the history section.

3. Reference Table: Use the reference table to learn Roman numeral values.

4. Reset: Click "Reset All" to clear all inputs, results, and history.

5. Keyboard Shortcuts: Press Enter to convert, Escape to reset.

Understanding Roman Numerals

Basic Symbols: I=1, V=5, X=10, L=50, C=100, D=500, M=1000

Subtractive Notation: When a smaller numeral appears before a larger one, it's subtracted (e.g., IV=4, IX=9, XL=40).

Additive Notation: When a smaller numeral appears after a larger one, it's added (e.g., VI=6, XI=11, LX=60).

Vinculum Notation: For numbers above 3,999, a line over a numeral multiplies it by 1,000 (e.g., V̅=5,000, X̅=10,000, M̅=1,000,000).

Maximum Value: This converter supports up to 3,999,999 (M̅M̅M̅C̅M̅X̅C̅I̅X̅CMXCIX).

About the Roman Numeral Converter

This tool converts ordinary numbers into Roman numerals and Roman numerals back into numbers. Enter a number such as 2024 to get MMXXIV, or enter a numeral like XIV to get 14. It works in both directions automatically, detecting whether you have typed digits or letters.

How the Roman system works

Roman numerals use seven letters with fixed values: I is 1, V is 5, X is 10, L is 50, C is 100, D is 500, and M is 1000. Numbers are built by combining these, generally from largest to smallest, adding the values together. So MMXXIV is 1000 plus 1000 plus 10 plus 10 plus 4. The system has no symbol for zero and no place value, which is part of why it was eventually replaced for calculation by the decimal system we use today.

The subtractive rule

The clever part of Roman numerals is subtraction. To avoid writing four identical symbols in a row, a smaller value placed before a larger one is subtracted rather than added. So 4 is IV (one before five) not IIII, and 9 is IX (one before ten). This applies in specific pairs: I before V or X, X before L or C, and C before D or M. The converter applies these rules automatically so the output follows standard form rather than a naive repetition.

The practical range

Standard Roman numerals run from 1 to 3999. There is no zero and no negative numbers, and representing values above 3999 requires bars over letters to multiply them by a thousand, a notation rarely used today. This tool works within the conventional 1 to 3999 range, which covers virtually every modern use.

Where Roman numerals are still used

Despite being ancient, Roman numerals persist in many places: clock faces, the copyright year on films and broadcasts, book chapter and volume numbers, the names of monarchs and popes, Super Bowl numbering, and building cornerstones. Knowing how to read and write them remains genuinely useful, and converting longer numerals by hand is error-prone, which is where this tool helps.

Tips and related tools

When decoding, the tool reads numerals case-insensitively, so xiv and XIV both work. If you enter an invalid numeral it will flag it rather than guess. For spelling numbers out in words instead, see the Number to Words Converter, and for converting between number bases the Number Base Converter. Everything runs instantly in your browser.

Frequently Asked Questions

What range is supported?

1 to 3999, the standard Roman numeral range.

How do I convert back?

Enter a Roman numeral like XIV and it returns the number.

Are lowercase numerals accepted?

Yes, they are read case-insensitively.

What about zero?

Romans had no zero, so 0 is not represented.

Where does the conversion run?

Entirely in your browser. Your data is never uploaded to a server.