Roman Numeral Converter

Convert numbers to Roman numerals and Roman numerals back to numbers, instantly in either direction.

Number → Roman Numeral

Number (1–3999)

MMXXVI

Roman Numeral → Number

Roman Numeral

2026

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Why use Roman Numeral Converter?

Roman numerals use combinations of letters (I, V, X, L, C, D, M) to represent numbers, with subtractive notation for numbers like 4 (IV) and 9 (IX). This tool converts in both directions — enter a number to get its Roman numeral, or enter a Roman numeral to get its numeric value — supporting the standard range of 1 to 3999.

Key benefits

Supports the full standard range (1-3999)
Validates input and flags invalid numerals
Instant bidirectional conversion

Features

Number-to-numeral and numeral-to-number conversion
Standard subtractive notation (e.g. IV, IX, XL)

Popular use cases

Looking up the Roman numeral for a year (like a movie copyright date)
Decoding a Roman numeral on a clock face or monument
Checking homework or a school assignment on Roman numerals

How to use Roman Numeral Converter

1
Convert a number
Enter a number from 1 to 3999 to see its Roman numeral.
2
Or convert a numeral
Enter a Roman numeral to see its numeric value.

Frequently asked questions

Why is the maximum 3999?

Standard Roman numerals don't have a symbol for 5000 or beyond in common usage, so 3999 (MMMCMXCIX) is the largest value representable with standard notation.

Does this support lowercase Roman numerals?

Input is automatically uppercased before conversion, so lowercase input like "mmxxvi" works the same as "MMXXVI".

Last reviewed: July 2026

Number → Roman Numeral

Roman Numeral → Number

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