Roman Numeral Converter

What is the Roman Numeral Converter?

The Roman Numeral Converter turns ordinary numbers into Roman numerals and Roman numerals back into ordinary numbers, instantly and both ways. Type 2024 and you get MMXXIV; type MCMXC and you get 1990. Romans built their counting system from just seven letters — I, V, X, L, C, D and M — and that system still shows up everywhere: on clock faces, in book chapters, after kings' and popes' names, on movie copyright lines, and on the Super Bowl logo. This tool exists to take the guesswork out of reading and writing those numerals, so you can get a correct answer in one second without memorising the rules.

How to use it

1. To go from a normal number to a Roman numeral, type a whole number from 1 to 3999 into the number box. The Roman form appears as you type.
2. To go the other way, type a Roman numeral (in any case — lowercase is fine) into the Roman box, and the everyday number appears instantly.
3. To write a date, pick a day in the date helper and each part is converted separately for you.
4. Tap or click the copy button to grab the result for a tattoo brief, a document, or a message. No sign-up, no waiting, no data leaving your browser.

The method behind it

Roman numerals are built from seven base symbols: I = 1, V = 5, X = 10, L = 50, C = 100, D = 500 and M = 1000. To build a number, you write these symbols from largest to smallest and add their values together — so 2024 is M + M + X + X + I + V (MMXXIV). The clever part is subtractive notation: when a smaller symbol sits directly in front of a larger one, it is subtracted instead of added. That is why 4 is IV (5 minus 1) rather than IIII, and 9 is IX (10 minus 1). The same trick gives XL for 40, XC for 90, CD for 400 and CM for 900. To convert in reverse, the tool reads the symbols left to right and applies that same add-or-subtract rule. The standard system covers 1 to 3999; beyond that, historical texts placed a bar over a symbol to multiply it by 1000, which is almost never needed today.

Examples

• 4 becomes IV — the classic subtractive form, not IIII.
• 49 becomes XLIX — that is XL (40) followed by IX (9).
• 2024 becomes MMXXIV — two thousands, two tens, and four.
• MCMXC reads as 1990 — M (1000) + CM (900) + XC (90).
• A wedding date like 14 / 6 / 2025 becomes XIV · VI · MMXXV when each part is converted separately.

Common use cases

• Tattoos and jewellery: turning a birth year, anniversary, or meaningful number into clean Roman numerals before sending it to an artist.
• Sports: decoding event numbers such as the Super Bowl (Super Bowl LVIII = 58) or Olympic-style numbering.
• Books and outlines: numbering chapters, prefaces, volumes, and appendices the traditional way.
• Dates and copyright: writing years on certificates, plaques, and film credits (many movies still stamp the year in Roman numerals).
• Schoolwork: checking homework answers and learning how subtractive notation works.

Why use this one

Most Roman numeral pages only go one direction or split the two directions across separate thin pages. This one does both in a single screen, so you never switch tabs. It is built with real dates and years in mind, handles the full 1–3999 range cleanly, and shows the underlying I/V/X/L/C/D/M rules so you actually learn the pattern instead of blindly copying. Everything runs in your browser — instant, private, no account — and the answer is one tap away from your clipboard.

It is part of a small, focused converters toolkit. To switch numbers between binary, octal, decimal and hex, the Number Base Converter handles every base both ways. To convert temperatures, the Celsius to Fahrenheit tool flips between the two scales, and the Cm to Inches converter turns lengths back and forth with a reference table.

Frequently asked questions