Roman Numeral Converter

This free Roman numerals converter turns any number into Roman numerals, reads Roman numerals back into ordinary numbers and writes full dates in Roman form. It handles everything from a simple number to Roman numeral conversion up to 3,999,999 with vinculum (overline) support, all in your browser with a clear step-by-step breakdown — perfect for tattoos, films, book chapters, clock faces and homework.

What Is a Roman Numeral Converter?

A Roman numeral converter turns ordinary Arabic numbers into Roman numerals and back again. Roman numbers are an ancient additive-subtractive system that uses seven Roman letters — I, V, X, L, C, D and M — to represent values. They are still everywhere today: on clock faces, in book chapters, in movie copyright years, on monuments and in the names of monarchs and popes. This free online tool converts numbers from 1 to 3,999,999, reads Roman numerals back into numbers, and even writes full dates in Roman form.

The Seven Roman Numeral Symbols

Every Roman numeral is built from these base symbols. Larger symbols are written to the left, smaller ones to the right, and the values are added together — except when the subtraction rule applies.

The Subtraction Rule

When a smaller symbol appears before a larger one, it is subtracted instead of added. This keeps numerals short and avoids long runs of the same letter. Only six subtractive pairs are valid:

• IV = 4 and IX = 9 — I before V or X.
• XL = 40 and XC = 90 — X before L or C.
• CD = 400 and CM = 900 — C before D or M.

Combinations such as IL, IC, VX, LC or DM are not allowed. Because of this rule, 1999 is written MCMXCIX (M + CM + XC + IX), not the longer MIM.

How to Convert a Number to a Roman Numeral

1. Break the number into place values: 2026 = 2000 + 0 + 20 + 6.
2. Convert each part: 2000 = MM, 20 = XX, 6 = VI.
3. Join them largest to smallest: MM + XX + VI = MMXXVI.
4. Apply the subtraction rule where 4s and 9s appear (40 → XL, 9 → IX, and so on).

This tool does all of that automatically and shows you the step-by-step breakdown, so you can see exactly which symbol contributes which value.

Numbers Above 3999: Vinculum Notation

With the standard symbols you can only reach 3999, because M may be repeated at most three times. To write larger numbers, Romans used the vinculum — a horizontal bar drawn above a symbol that multiplies its value by 1000.

This converter supports vinculum notation and displays any number of 4,000 or more with overlined symbols, reaching all the way up to 3,999,999.

Writing Dates in Roman Numerals

Dates are commonly written in Roman numerals on cornerstones, certificates, film credits and gravestones. There are two approaches: convert day, month and year separately and join them with dots (23 April 2026 → XXIII.IV.MMXXVI), or show only the year (MMXXVI). The Date → Roman tab in this tool produces both forms at once.

Why Roman Numerals Have No Zero

The Roman system is purely additive and subtractive, so there is no symbol for zero — the concept of zero arrived later from Indian mathematics together with Arabic numerals. This is also why the system cannot express fractions or negative numbers and always starts from 1.

Common Roman Numbers Reference Chart

Whether you need a quick number to Roman numeral lookup for a date, a chapter or a tattoo, this chart of frequently used Roman numbers covers the values people search for most:

To convert any other value, just type it into the Roman numerals converter above — the result and a full breakdown appear instantly. For more questions, see the FAQ section below.