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Roman Numeral Converter

Convert numbers to Roman numerals and Roman numerals back to numbers, from 1 to 3,999, with the working shown.

Results

ItemValue

Steps

StepWorking
Standard Roman numerals run from 1 (I) to 3,999 (MMMCMXCIX). There is no Roman numeral for zero. Larger numbers used a bar over a letter to multiply it by 1,000, which is not shown here.

Quick Answer

Roman numerals use seven letters: I = 1, V = 5, X = 10, L = 50, C = 100, D = 500 and M = 1,000. Add values from left to right, but when a smaller letter comes before a larger one, subtract it. So 1994 = M (1,000) + CM (900) + XC (90) + IV (4) = MCMXCIV.

Last updated: 2 November 2026 ·How we calculate this: standard subtractive Roman numeral rules

Table of Contents

How This Roman Numeral Converter Works

Type a number or a Roman numeral. The converter works out which way to go. Numbers are built from the largest value down, and Roman numerals are read from left to right, subtracting where a small symbol comes before a larger one. It also checks that numerals are written in the standard way.

Quick explanation: add symbols from largest to smallest, and use the six subtractive pairs: IV, IX, XL, XC, CD and CM.

  • Range: 1 to 3,999.
  • Upper or lower case: both work.
  • Validity check: forms such as IIII or IC are flagged.

How to Use the Roman Numeral Converter

  1. Type a whole number from 1 to 3,999, or a Roman numeral.
  2. Press Calculate.
  3. Read the converted number or numeral.
  4. Check the steps table to see how each symbol adds up.
  5. If you see an error, check the numeral follows the standard rules.

The Rules

  1. Symbols: I 1, V 5, X 10, L 50, C 100, D 500, M 1,000.
  2. Add: symbols of equal or smaller value that follow are added: VI = 6.
  3. Subtract: a smaller symbol before a larger one is subtracted: IV = 4.
  4. Only six subtractive pairs: IV, IX, XL, XC, CD and CM.
  5. Repeats: I, X, C and M can repeat up to three times. V, L and D never repeat.

Key Terms

  • Roman numerals: an ancient number system using the letters I, V, X, L, C, D and M.
  • Subtractive notation: writing a smaller symbol before a larger one to subtract it, as in IX = 9.
  • Additive notation: adding symbols together, as in XII = 12.
  • Vinculum: a bar over a numeral that multiplies it by 1,000.

Worked Example

Convert 2026 to Roman numerals.

  • 2,000 = MM
  • 20 = XX
  • 6 = VI
  • 2026 = MMXXVI

Real-Life Examples

  • A tattoo date: 14 February 2015 is XIV · II · MMXV.
  • A film’s copyright year: MCMLXXXV at the end of the credits is 1985.
  • Super Bowl numbers: Super Bowl LX is the 60th Super Bowl.
  • A wedding date: 2026 is written MMXXVI, and 2030 is MMXXX.
  • Book chapters: Chapter XLVII is chapter 47, because XL is 40 and VII is 7.

Roman Numerals vs Arabic Numerals

  • Roman numerals: letters that add and subtract, with no zero and no place value.
  • Arabic numerals: the digits 0 to 9, where a digit’s position sets its value.
  • Why we switched: place value and zero make arithmetic far easier.
  • Today: Roman numerals are mainly used for style, order and tradition.

Roman Numeral Chart

NumberRomanNumberRoman
1I20XX
2II30XXX
3III40XL
4IV50L
5V90XC
6VI100C
7VII400CD
8VIII500D
9IX900CM
10X1000M

Where Roman Numerals Are Used

  • Clocks and watches: often with IIII instead of IV for 4 o’clock.
  • Names: kings, popes and family names, such as Henry VIII or John Smith III.
  • Events: the Super Bowl and the Olympics use Roman numerals.
  • Books and films: chapters, volumes and copyright years.

Common Mistakes to Avoid

  • Writing IIII for 4. The standard form is IV.
  • Subtracting from too large a value. 99 is XCIX, not IC.
  • Repeating V, L or D. 10 is X, not VV.
  • Repeating a symbol four times. 40 is XL, not XXXX.
  • Looking for zero. Roman numerals have no symbol for zero.

Frequently Asked Questions

MMXXVI.

M.

IV. On some clocks you will see IIII, but IV is the standard form.

MMMCMXCIX, which is 3,999.

No. The Romans had no symbol for zero.

40, because X (10) comes before L (50), so you subtract: 50 − 10.

M (1,000) + CM (900) + XC (90) = 1990.

L.

XCIX: 90 (XC) plus 9 (IX). IC is not a standard form.

It is a long clockmaking tradition. One common explanation is that IIII balances the VIII on the other side of the dial.

Enter the year above. For example, 1990 is MCMXC and 2000 is MM.

Yes. Lowercase forms such as iv and xii are often used for page numbers in book introductions.

A bar over a numeral, called a vinculum, multiplied it by 1,000. For example, V with a bar meant 5,000.

The Romans used a separate system based on twelfths for fractions, but it is rarely used today.

References & Sources

SourceUsed ForLink
Wikipedia, Roman numerals Symbols and rules. https://en.wikipedia.org/wiki/Roman_numerals
Encyclopaedia Britannica, Roman numeral History of the system. https://www.britannica.com/topic/Roman-numerals