Math

Roman Numeral Converter

Convert whole numbers from 1 to 3999 into Roman numerals and Roman numerals back into numbers, with worked examples for 2026, 1994 and 49.

Inputs

Results update as you type — essentials first

Saved scenarios

Store input snapshots on this device — load anytime.

No saved scenarios yet.

Formula / how it works

Symbols: I=1, V=5, X=10, L=50, C=100, D=500, M=1000. Subtractive pairs: IV=4, IX=9, XL=40, XC=90, CD=400, CM=900. Write each digit of the number separately, thousands first.

Detailed guide

What it is, how to use it, how to read the numbers, common mistakes, a worked example, formulas, and FAQs.

What this calculator is

Roman numerals write numbers with letters, and they are still used on clocks, in book chapters, film dates and monarchs' names. The system builds numbers by adding symbols, with a small symbol before a larger one meaning subtraction. This tool converts a whole number from 1 to 3999 to a Roman numeral, and a Roman numeral back to a number. The standard form has a few rules. A symbol is repeated no more than three times in a row, and only the six subtractive pairs are used. The range stops at 3999 because standard notation repeats M at most three times. There is no zero and no fractions in the classical system.

When to use / who it helps

  • You need to write a year, such as 2026, as a Roman numeral.
  • You are reading a Roman numeral date or chapter number.
  • You are checking a number for a tattoo, cake or invitation.
  • You are completing homework.
  • You are numbering an outline or a sequel.

How to use

Steps

  1. Choose the direction: number to Roman, or Roman to number.
  2. Enter a whole number between 1 and 3999, or a Roman numeral.
  3. Read the converted result.
  4. For a year, convert each part, thousands, hundreds, tens and units.
  5. Check the answer by adding the symbol values.
  6. Use capital letters for Roman numeral input.

How to interpret results

  • Symbols are read from left to right and added, except for subtractive pairs.
  • The largest standard value is 3999, MMMCMXCIX.
  • A symbol before a larger one is subtracted.
  • There is no Roman numeral for zero in this system.
  • Invalid sequences like IIII or VX are not standard.

Common mistakes & gotchas

  • Writing 4 as IIII.
  • Writing 99 as IC instead of XCIX.
  • Entering 0 or numbers above 3999.
  • Using lowercase or invalid letters.
  • Subtracting more than one symbol, such as IIX for 8.

Worked example

Worked example — 2026, 1994 and 49

  1. 2026 = 2000 + 20 + 6 = MM + XX + VI = MMXXVI.
  2. 1994 = 1000 + 900 + 90 + 4 = M + CM + XC + IV = MCMXCIV.
  3. 49 = 40 + 9 = XL + IX = XLIX.
  4. Check XLIX: XL is 50 − 10 = 40 and IX is 10 − 1 = 9, so 40 + 9 = 49.

Result: 2026 is MMXXVI.

To load the form's own demo values, tap Try example above the Calculate button.

How to calculate / formula

Symbols: I=1, V=5, X=10, L=50, C=100, D=500, M=1000. Subtractive pairs: IV=4, IX=9, XL=40, XC=90, CD=400, CM=900. Write each digit of the number separately, thousands first.

Frequently asked questions

How do I write 2026 in Roman numerals?

MMXXVI.

What is the largest Roman numeral here?

3999, written MMMCMXCIX.

Why is 4 written IV?

A smaller symbol before a larger one is subtracted: 5 − 1.

Is there a Roman numeral for zero?

No, not in the classical system.

Can I repeat a symbol four times?

Standard notation allows at most three in a row.

How do I read MCMXCIV?

M (1000) + CM (900) + XC (90) + IV (4) = 1994.