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Roman Numeral Converter – Numbers and Roman Numerals

Write any number from 1 to 3,999 in Roman numerals, or read a Roman numeral back as a number. Each answer is broken into its parts, so you can see exactly how it is built.

Number to Roman numerals

MCMXCIV

Breakdown

  1. M1,000
  2. CM900
  3. XC90
  4. IV4

Roman numerals to number

2,026

Breakdown

  1. M1,000
  2. M1,000
  3. X10
  4. X10
  5. V5
  6. I1

A bar over a numeral multiplies it by 1,000, so V̅ is 5,000. Without the bar, Roman numerals stop at 3,999.

Roman numeral symbols

I
1
V
5
X
10
L
50
C
100
D
500
M
1,000

How to use the Roman numeral converter

  1. To write a number in Roman numerals, type it in the Number box of the first calculator. The numeral appears straight away, with a Copy button.
  2. To read a Roman numeral, type it in the Roman numeral box of the second calculator. The value appears underneath.
  3. Check the Breakdown under each answer. It splits the numeral into parts, such as MCMXCIV = M + CM + XC + IV, with the value of each part.
  4. For numbers above 3,999, switch on Allow numbers up to 3,999,999 (vinculum).

Features

  • Both directions at once: number to Roman numerals and Roman numerals to number.
  • Step-by-step breakdown of every numeral into thousands, hundreds, tens and units.
  • Helpful error messages for invalid numerals such as IIII, VV, VX or IC, with the value the usual rule gives and its correct spelling.
  • Vinculum option for numbers up to 3,999,999.
  • Symbol chart for quick reference, including barred symbols when the vinculum is on.

How Roman numerals work

Roman numerals are written from the largest value to the smallest and added together, so XVI is 10 + 5 + 1 = 16. The one exception is subtraction: when a smaller numeral comes directly before a larger one, it is taken away. Only six such pairs are used, which is why 1994 is written M + CM + XC + IV, meaning 1,000 + 900 + 90 + 4.

The easiest way to convert a number by hand is to work through its digits. For 1994, write 1,000 as M, 900 as CM, 90 as XC and 4 as IV, then join them: MCMXCIV. The converter's breakdown follows exactly these steps.

Common mistakes the converter catches

  • Too many repeats: IIII should be IV, and XXXX should be XL.
  • Repeating V, L or D: VV isn't used because X already means 10.
  • Invalid subtractions: IC for 99 should be XCIX, and XM for 990 should be CMXC.
  • Wrong order: IXI and IIX aren't standard; the message shows what the usual reading rule would give and how that value should be written.

Where you still see Roman numerals

Roman numerals appear in book chapters, the names of kings, queens and popes, film copyright years, clock faces, outline headings and events such as the Olympic Games. Copyright notices at the end of films are a classic puzzle: MCMLXXXV is 1985 and MMXXIV is 2024.

Why use Fileora's Roman numeral converter

It checks your numeral against the standard rules rather than guessing, explains every answer, and works both ways on one screen. It is free, private and runs in your browser.

To write a number out in words instead, use the number to words converter. For other number systems, the binary converter handles binary, octal and hexadecimal.

Frequently asked questions

What are the seven Roman numeral symbols?

I is 1, V is 5, X is 10, L is 50, C is 100, D is 500 and M is 1,000. Every Roman numeral is built from these seven letters, and the converter shows them in a small chart below the two calculators.

How do you write 2026 in Roman numerals?

2026 is MMXXVI: MM for 2,000, XX for 20 and VI for 6. Type 2026 in the Number box and the breakdown shows each part with its value.

Why is 4 written IV and not IIII?

Standard Roman numerals never repeat a symbol more than three times. Instead, a smaller numeral placed before a larger one is subtracted, so 4 is IV (5 minus 1) and 9 is IX. Many clock faces do show IIII for 4, but it isn't the standard form, and the converter points this out if you type it.

Which subtractions are allowed?

Only six: IV (4), IX (9), XL (40), XC (90), CD (400) and CM (900). I can only come before V and X, X only before L and C, and C only before D and M. So 99 is XCIX, not IC, and 49 is XLIX, not IL.

What is the largest Roman numeral?

With the standard symbols, the largest is 3,999, written MMMCMXCIX. For larger numbers the Romans drew a bar, called a vinculum, over a numeral to multiply it by 1,000. Turn on the vinculum option and the converter writes numbers up to 3,999,999 this way, so 5,000 becomes V with a bar over it.

Is there a Roman numeral for zero?

No. The Roman system had no symbol for zero, and it had no negative numbers or fractions in this form either. The converter tells you if you type 0, a negative number or a decimal.

Can I type Roman numerals in lowercase?

Yes. Lowercase letters such as mcmxciv are read as uppercase, and spaces are ignored, so you can paste a numeral straight from a document or a film's closing credits.

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